What is a user?

Comprehensive and Detailed Explanation From Exact Extract of ITIL 4 Managing Professional Transition:

According to ITIL 4, a user is defined as “a person who uses services.”

Users are distinct from customers or sponsors.

A customer is the person who defines the requirements for a service and takes responsibility for outcomes.

A sponsor is the role that authorizes the budget for service consumption.Therefore, the role that uses the service is referred to as a user, making Option B correct.