Cool air acts as a barrier over which warmer, less dense air rises, in a process? divergence orographic lifting

The answer is frontal wedging. Hope this helps!

Frontal Lifting

Explanation:

This a process where the warm air being lighter is uplifted by the colder air from below and the resultant cold air acts as barrier for the warm air to develop at the ground surface and as being heavy on weight it stays under the warm air, this leads to the formation of convergent uplifting and the two distinct mass air move and the fronts may produce a cyclone when the air moves in a cyclic pathway.

Answerepicenter;