Wild-type Neurospora was treated with X-rays to induce heritable mutations. Treated Neurospora was grown on minimal medium ("no addition" in the table) and minimal medium supplemented with the compounds indicated in the table. Growth is indicated as dry weight of fungal material after 5 days. Here we see the results of three mutated strains that were linked to the metabolic pathway that generates arginine. Without arginine production, Neurospora cannot grow.
Considering the biochemical pathway of arginine production, which strain harbors a mutation in the enzyme that converts ornithine to citrulline?
a) Strain A
b) Strain B
c) Strain C
d) None of the above