(B) Pleasant personality

A pleasant personality may be a positive characteristic, but it alone is not a definitive sign of good mental health. Mental health involves a broader range of factors, including emotional well-being, coping mechanisms, resilience, self-awareness, and the ability to maintain a positive and stable mental state.

Other options provided in the question, such as (A) control over emotions, (C) balanced feelings and desires, and (D) ability to accept the realities of life and face them, are more directly associated with good mental health. These traits indicate emotional regulation, adaptability, and a healthy mindset, which are essential aspects of mental well-being.