Confused with Modulation/Demodulation

[Cuntryboner]

Hi, Doing a problem on modulation and demodulation from VCAA 2006 exam.
Here is how I explained the two in the context of the question.

1. Modulation: Transforming the electronic information signal, which was an acoustic energy form into a light information signal, so it can be transferred at a high speed between points p and q

2. Demodulation: Transforming the light/optical signal back into an electrical signal so it can be easily manipulated into sound energy by the loud speaker

This is however incorrect according to Assessment report.
Modulation: Variation of Light intensity
De-Modulation: Variation of Light intensity produced an electronic signal

I am confused, as this answer, I feel doesn't explain the function of these two concepts, in the context of  the question.
Any clarification is greatly appreciated

[Akirus]

You just need to mention that the time variation in the amplitude of the electrical signal is transferred to the same time variation in the intensity of the higher-frequency light carrier wave. This reduces attenuation in transmitting the information across the system.

Your answer is incomplete because simply mentioning the conversion from light to electricity does not explain how the information in the signal is being transferred.

[Cuntryboner]

Oh I get it. Just need to pretty up what I have then?