Two spheres `A` and `B` have the same radii but the capacity of `A` is greater than that of `B`. The surfaces of both are painted black. They are heated to the same temperature and allowed to cool in vacuum. Then,

Options

A. `A` cools faster than `B`
B. both `A` and `B` cool at the same rate
C. at any temperature the ratio of their rates of cooling is a constant
D. `B` cools faster than `A`