Which definition best fits the word "obtuse"?

The definition that best fits the word "obtuse" in this context is that it means confusing and unclear. This interpretation aligns with one of the commonly accepted meanings of "obtuse," particularly when used to describe a person's thinking or understanding. An obtuse individual may be perceived as slow to grasp concepts, lacking insight, or unable to comprehend something that is straightforward to others, thus rendering the situation or communication confusing or unclear.

The other definitions refer to qualities that are more aligned with clarity, perception, and depth, which do not capture the essence of "obtuse." Therefore, understanding the nuances of the word in terms of comprehension and clarity supports why this particular choice is the most fitting.