I think B
STEP-by STEP EXPLANATION
<span>Chemical reaction: CH</span>₃COO⁻(aq) + H⁺(aq) ⇄ CH₃COOH(aq).
H⁺ is from HNO₃: HNO₃ → H⁺ + NO₃⁻.
<span>A buffer can
be defined as a substance that prevents the pH of a solution from changing by
either releasing or absorbing H</span>⁺ in a
solution.
Buffer is a solution
that can resist pH change upon the addition of an acidic or basic components
and it is able to neutralize small amounts of added acid or base, pH of
the solution is relatively stable.
I take that the insects remain constant no matter what happens to the frogs (which the frogs eat presumably). So a constant food supply for the frogs is not the problem.
The line for the alligators increases over time. It their numbers increase, the frogs are in trouble. The alligators will pursue lunch with determined single mindedness and there are more of them around.
So the frogs should decrease. Their natural enemy is the alligator and alligators won't go after insects. It's not worth their time.
A is the only answer you can choose.