I can only answer from prior knowledge learnt in physics about nuclear power plants.
The answer (i think) is A.
I'd suggest doing some research or asking someone on the physics board who probably knows more than me but the gist of it is (using Uranium as an example) you bombard the Uranium sample with neutrons making the atom unstable and so it breaks into two smaller (daughter) nuclei and releases energy in the process. This way of creating power used in nuclear power plants is nuclear fission whereas fusing atoms together and releasing energy is nuclear fusion.
Hopefully if I'm wrong someone will clarify, but that's all I would think you'd need to know
In an atom, there are two main types of forces; the electrostatic force between protons acting to tear the nucleus apart, and the aptly named "strong" nuclear force, which is a very close-range force that acts between nucleons (protons and neutrons) to hold the nucleus together. It is a close range force in that its strength drops off faster than 1/r^2 like the electrostatic force. If your atom is too large, then the strong nuclear force acting on nucleons at the opposite ends of the atom start to weaken. However, the addition of more protons only increases the repulsive force. Eventually, the strong nuclear force isn't strong enough to keep the atom together as the atom is too large; the repulsions between the protons on opposite sides of the nucleus become too great. That's why there is an upper limit to the size of stable nuclei.
Now, if you have a tiny nucleus, you don't have many nucleons to provide the strong force. Let's look at hydrogen. In the sun, when hydrogen undergoes nuclear fusion, the high temperatures allow the hydrogen nuclei (the massive temperatures strip atoms of their electrons) to overcome the electrostatic repulsions for the strong force to act, and the two protons fuse. Immediately, one of the protons decays into a neutron as the magnitude of the strong force between a proton and neutron is the same for two protons, but the neutron doesn't repel the proton. Here, the atom has increased in size, but as the strength of the strong force is just so large at such small atomic radii, energy is released. In massive stars, more and more massive nuclei are fused eventually to form iron, all relying on the principle that the strength of the strong force means fusing nuclei released energy. Suddenly, with iron, we've reached the maximum energy per nucleon. For a nucleus larger than iron's, the strong force starts to weaken at the edges of the atom as I've mentioned above. As the nucleus gets larger and larger, the strong force continues to weaken. Therefore, with a massive nucleus like uranium, splitting the nucleus up releases energy because the lower number of nucleons to hold the nucleus together is more than balanced by the reduction of the electrostatic repulsions and the reduction in atomic size, which leads to an increase in the strength of the strong force. This (from my understanding) is why energy is released when uranium is bombarded by neutrons.
Is there any way molecular iodine can be soluble in water? For my Chemistry SAC I put down that it was aqueous because I couldn't see any solids in the solution and went against the solid state provided in the electrochemical series. lol It was in solution with potassium iodide, which I found out makes iodine soluble in water by converting it to an ionic form, but I'm guessing I'm still wrong. 
Oh well, my bad. XD
Yay triiodide ion. It's a pity VCE doesn't show us much. If you can't see the solid, what else can you say? That it's a solid? Your teacher would have a tough time putting up a case against what you've written.
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