From the cross aa × aa, the probability of producing a homozygous dominant offspring is
a. 75%.
b. 50%.
c. 25%.
d. 100%.

I think it is 25%. When you draw a genetic diagram for Aa and Aa the results are AA - homozygous dominant, Aa - heterozygous dominant, Aa - heterozygous dominant and aa - homozygous recessive. So that is 1 out of 4, therefore 25%.

The answer is a i believe