I'll email 'em.
Because I'm 100% about q3 being DNA replacement because even VCAA mentions in 08 examiners report:
"Gene therapy aims to insert a normal/functioning allele into a cell.
An example of incorrect information provided by students was ‘the removal of an allele or the insertion of an allele into
the body’."
The question said: "Defective alleles may result in genetic defects. Replacement of a defective allele with a normal allele is called:
A- Cell cloning
B - gene therapy
C - Triplet change
D - DNA replacement."
REPLACING a defective allele clearly implies, REMOVING, then INSERTING the allele, and so i dont think gene therapy is right, unless im missing out on something here.