Respuesta :
Answer: Option (A) and (D)
Explanation: Isostacy is the gravitational state of equilibrium in which a block sinks down due to the addition of materials and also the same block rises up if materials are eroded.
In terms of our earth, the gravitational force is responsible for the sinking or down-pushing of the continents, and the bouyancy forces in the mantle is responsible for the uplifting of the continents.