Normally, Neurospora Can Synthesize All 20 Amino Acids

Normally, Neurospora can synthesize all 20 amino acids. A certain strain of this mold cannot grow in minimal nutritional medium, but grows only when the amino acid leucine is added to the medium. This strain

A) is dependent on leucine for energy.
B) has a mutation affecting a biochemical pathway leading to the synthesis of carbohydrates.
C) has a mutation affecting the biochemical pathways leading to the synthesis of all 20 amino acids.
D) has a mutation affecting the biochemical pathway leading to the synthesis of leucine.
E) has a mutation affecting the biochemical pathways leading to the syntheses of 19 of the 20 amino acids.