Final answer:
Senior managers require conceptual, interpersonal and leading skills more than technical skills, which are less necessary as one moves up in management roles.
Step-by-step explanation:
The least necessary skill for senior managers is likely to be technical skills. Senior management roles typically focus more on conceptual, interpersonal, and leading skills. Technical skills are more essential at the lower levels of management where the day-to-day operations and specialized tasks are executed. As managers rise to senior positions, they rely more on their ability to visualize the organization as a whole, formulate strategic plans, lead teams, and maintain working relationships with a wide range of stakeholders.