Which of the Following Is NOT Proposed to Explain the Change

Which of the following is NOT proposed to explain the change in clutch size of birds with latitude?

A) Clutch size has evolved to equal the largest number of young the parents can feed.
B) Clutch size results from different allocations of energy to egg production, avoidance of predators, and competition.
C) Clutch size is a fixed evolutionary feature within any given taxonomic lineage of bird species.
D) Clutch size varies in direct proportion to seasonal variation in resources, especially food.