Answer:
A. Ad hominem fallacy.
Step-by-step explanation:
An ad hominem fallacy is a type of logical reasoning where the attack is focused on the person or individual rather than the claim or argument made. In other words, this type of fallacy attacks the person making the argument and not the argument itself. This type of fallacy is also known as a personal attack fallacy or name-calling.
In the given statement. the speaker comments on the knowledge of the opponent with regards to the issue of "fiscal responsibility", focusing his attack on the personal level and not on the issue. This is a direct attack on the opponent and thus, falls into the ad hominem fallacy.
Thus, the correct answer is option A.