Thought here would be a good place to complain. I have an issue with the wording of answer A. Logically, it reads as:
there exists f(x) s.t. ~(P^Q)
due to it saying “without both” as opposed to “with neither”, which from the explanation (and the fact I got this wrong) is definitely what the testmakers really meant to say, aka:
there exists f(x) s.t. ~P^~Q
Suggestion for how to rewrite option A: “There exists a function with neither a maximum nor a minimum that is a real number”.