What does Leo not understand about his sister's reaction?

Leo's confusion regarding his sister's reaction centers on her opposition to his plan. This indicates that he is trying to comprehend the reasons behind her disagreement. In such situations, it is common for individuals to expect support or at least some understanding from close family members regarding their ideas or ambitions. Therefore, when faced with opposition, it can be particularly perplexing. Understanding the reasons for this conflict often involves considering emotional, psychological, or situational factors, which might not be immediately clear to Leo.

The other options do not accurately capture the essence of Leo's misunderstanding. For example, if he were confused about her support, indifference, or lack of discussion, it would suggest a different aspect of their relationship or communication that is not the core issue here. B is the most appropriate choice, as it directly relates to his inability to grasp why she stands against his plan, which is a reaction that can significantly affect the dynamics of their relationship.