Which of the Following Contradicts the "One- Gene, One- Enzyme

Multiple Choice

Which of the following contradicts the "one- gene, one- enzyme hypothesis"?

A) A single antibody gene can code for different related proteins, depending on the splicing that takes place post- transcriptionally.
B) A mutation in a single gene can result in a defective protein.
C) Alkaptonuria results when individuals lack a single enzyme involved in the catalysis of homogentisic acid.
D) Sickle- cell anemia results in defective hemoglobin.