Answer:
Tension
Step-by-step explanation:
I don't think it's shearing because that's just when rocks crack and these appears to be on to large of a scale.
Gravity isn't the cause because the hanging wall rises.
It could be compression, but that isn't the best word to describe what's happening. Like yes they're compressing into each other but they're both forced to move so Tension makes more sense.
Good luck!