Answer:
b. the rate of destruction is equal to the rate of carbonate input.
Step-by-step explanation:
At the Calcite Compensation Depth(CCD) the rate of addition of calcite and dissolution of the mineral is the same. Below this depth, all calcite minerals are dissolved.
The CCD occurs at a depth of 3000-4000m. It varies from places to places within the ocean. Other factors play important roles in determining the CCD. Some of the factors are temperature and pressure.