Answer:
A increases, B and C decrease
Explanation:
Enzyme 1 uses A as substrate to produce B. In turn, B is the precursor of C.
If enzyme 1 is inactivated, A cannot be converted into B, so A will accumulate (its concentration will increase) while B's concentration decreases. Because B's concentration decreases, there won't be enough of it to produce C, so the concentration of C will also be lower than in a fully functional pathway.
