Before the Genetic Code Was Actually Known, Francis Crick Predicted

Multiple Choice

Before the genetic code was actually known, Francis Crick predicted that it was degenerate. What piece of evidence led him to make this prediction?

A) All proteins looked the same.
B) All proteins were made of amino acids.
C) He noted that the base composition of the DNAs of various bacteria varied greatly while the amino acid composition of their proteins varied much less.
D) He noted that the base composition of the DNAs of various bacteria varied little while the amino acid composition of their proteins varied greatly overall.
E) The code was non-overlapping.