Mutation a inactivates enzyme A in the pathway, mutation b inactivates enzyme B, and mutation c inactivates enzyme C. Mutant strains of bacteria, designated mutant a, b, or c, each have one of these defects. The mutant strains of bacteria were tested on minimal medium to which compound I, II, or III was added. The bacteria require compound III in order to grow. Place a plus or a minus in the table to designate if the mutant strain will grow on medium with that compound present. A plus indicates the mutant will grow, whereas a minus indicates that the mutant will not grow.