It is b divergent boundary
The answer is transform/conservative plate boundary where the plates slide past each other without producing or destroying plate materials. One example is the San Andreas Fault of California.
The other two plate boundaries are destructive and constructive plate boundary seperately,in which constructive plate boundary will produce plate material given the rising convection current of magma, and the plates would move in opposite directions.
While the other destroy plate materials given the sinking convection current of magma,plates colliding with each other.
Hope it helps!
The volume of the rectangular prism is 72
