The Activation of Amino Acids for Protein Synthesis Requires

The activation of amino acids for protein synthesis requires

A) one enzyme which activates all the amino acids.
B) one enzyme for forming amino acyl adenylates and one forming amino acyl tRNA.
C) several enzymes and DNA.
D) a different enzyme for each of the twenty amino acids used to make proteins.
E) a series of enzymes each with a broad specificity for amino acids of similar structure.