I already said it but its reactivity
Explanation:
It is given that,
Force applied to object, 
Position,
(b) The cross product of force and position vector is used to find the net torque about the z axis. It is given by :



or

The torque is acting in -z axis.
(a) The magnitude of torque is given by :


Hence, this is the required solution.
It desolves calcium carbonate causing plates to bend and faults to occur. Faults and plates moving cases the formation of caves.
-Hopes this helps :)
It’s going to be both answer A and B but if you can only answer one then it’s going to be B