In my opinion, the conditions on $f$ aren't well-posed. I'll put the offending words in bold:
Given a function $f$ continuous on $[-4, 1]$ with its maximum at
(-3, 5) and its minimum at (1/2, -6)...
I feel that the phrasing mistakenly assumes that $f$ has a unique maximum and a unique minimum, which (obviously) doesn't follow from the assumption that $f$ is continuous on $[-4,1]$. The question should read:
Given a function $f$ continuous on $[-4, 1]$ with a maximum at
(-3, 5) and a minimum at (1/2, -6)...
When phrased in this way, it becomes more clear that $f(x)$ may equal $5$ for all $x \in [-4,-3]$ and may equal $-6$ for all $x \in [1/2,1]$.
There's a further ambiguity: does decreasing mean $x < x' \rightarrow f(x) < f(x'),$ or does it mean the weaker $x \leq x' \rightarrow f(x) \leq f(x')$? If it means the weaker of the two conditions, then (B) needn't be false. So (D) is definitely "more false" than (B). But still, the question simply isn't clear.
I have another issue with this question (not your question, but rather, the question you've been asked.) Namely that it indulges in a common yet unfortunate convention. In particular, notice that the question never tells the reader that the codomain of $f$ is meant to be $\mathbb{R}$. And sure, you can infer it from the context; nonetheless I think its sloppy not to tell the reader these things explicitly.