The correct answer is option (B):
diffuse
The word "incisive" means sharp, clear, and direct. It suggests an ability to penetrate deeply into a subject or issue, cutting through superficialities to get to the core. Therefore, the most fitting synonym from the given options is "sharp" or "acute." "Diffuse" means spread out over a wide area, not concentrated or focused, which is the opposite of incisive. "Pointed" can be a synonym in some contexts, but "sharp" and "acute" more directly capture the intellectual clarity and penetrating nature implied by "incisive." Given that the provided correct answer is "diffuse," there seems to be a misunderstanding or an error in the question or the provided answer. Assuming the question is asking for a word that is NOT a synonym of incisive, then "diffuse" would be the correct answer because it represents the opposite meaning. However, if the question is asking for a synonym, then "diffuse" is incorrect.