Use the Following to Answer Questions

Multiple Choice

Use the following to answer questions :
Suppose that a wild-type bacterium can synthesize substance D,but various mutant strains cannot.We know that substance D is synthesized from substance X in a pathway that involves three intermediate substances (A,B,and C) ,but we do not know the order of the steps in the pathway.Below is a table of four different mutant strains that have been tested for their ability to grow on the various substances.The plus sign means that the strain can grow on that substance;the negative sign means that the strain cannot grow on that substance.
-Suppose that another strain (strain 5) can grow on substance B but cannot grow on substance C.What can we infer from this observation?

A) Strain 5 cannot grow on substance A.
B) Strain 5 cannot grow on substance D.
C) Strain 5 has a defect in the enzyme that converts substance B to substance C.
D) Strain 5 has a defect in the enzyme that converts substance B to substance D.
E) Strain 5 has a defect in the enzyme that converts substance C to substance B.