Is it possible for a pair of nonadjacent angles to share vertex a and and ab? if it's not possible explain your answer.

Adjacent angles are angles that have common side and common corner point between them. This common common is called common vertex.
It is not possible for non-adjacent angles to share vertex A and line AB. Non-adjacent angles can share only vertex, but not also a common line. Or they can share a common line, and not a vertex. If two angles share both vertex and common line, then they are 100% adjacent angles.

2.) is the most sense