The most important interpersonal skill of a person to work with others is his

The answer is A) Availability. Interpersonal skill is about how easily others can connect with you. A colleague brings a problem, a doubt or a half-formed idea only to someone who is reachable, listens and responds in time. That openness is the base on which trust and teamwork are built.

• Status is a position in a hierarchy, not a skill. Holding a rank does not make anyone easier to work with.
• Power is the ability to direct others, which often produces compliance rather than cooperation. It works against the openness the question asks about.
• Ability is technical or professional competence. It matters for performance, but it is not an interpersonal quality.

Core concept: approachability as a leadership trait. It links to the Mains theme of ethics and governance, where empathy and service orientation are treated as civil service values.

Trap: choosing Ability because it sounds like the most useful quality. The question asks about the interpersonal side of working with others, not about competence.