Answer:
role
Explanation:
Any person that is placed in a position that requires certain expectations to be fulfilled has a difficult time acting according to what is expected. The position is called role.
Ben has been promoted and he finds it difficult to perform the duties of a boss. His role is of a boss where he is expected to give orders and lead people.
He does not understand the intricacies of how a boss should behave. But later, he learns to adapt to his new role as a boss.
Hence, the question is referring to role.