Answer:
B
Step-by-step explanation:
A leader who helping someone else step into the task of handling more responsibility can be testing to see if they can handle it.
We can use the process of elimination here:
A, there is no "in-group" of leaders so that one does not make sense.
C, inviting someone to take more responsibility is not establishing a hierarchy and not showing that they are above you so that does not make sense.
D, inviting someone else to help lead isn't really establishing any form of competition.
Thus, B seems like the most logical choice.