D. upward.
A supervisor in Department 156 is moving into the Department 251 as a manager. This is an example of UPWARD movement.
In an organization/company, there is what we call horizontal and vertical career growth movement, vertical career growth basically means focusing on getting a promotion within the company, which means an upward movement, that is you have been promoted from one level to a higher level, horizontal career growth, on the other hand, means expanding and increasing your knowledge or skills within the company.