The first question seems to be way out of the VCE syllabus.
Question 2: A
This is because all the other mutations only affect a single amino acid. This (I think) is referred to as a point mutation. However, A causes all subsequent amino acids to be shifted and hence the translation 'reading frame' is moved as well, causing basically every single subsequent amino acid to change as well. These VERY drastic mutations are known as 'frame shift mutations'.
EDIT: Whoops this was in the tertiary section, hang on, I'll check my notes.
Question 1: Pretty sure it's C. The Calvin Cycle occurs in three basic steps; 1. Carbon fixation, 2. Reduction, 3. Regeneration of Ribulose. I assume the first two steps mentioned in the question refer to steps 1 and 2, so all that's left is the third step for which C seems to fit best since ribulose something something becomes RuBP again after a few steps.