The thermal capacity of a body refers to its ability to absorb and store thermal energy. In other words, it is a measure of how much heat a body can hold. The correct answer is option 1, which states that the thermal capacity of a body depends on the mass of the body only.

Option 2 suggests that the thermal capacity also depends on the shape of the body. However, the shape of the body does not influence its ability to hold heat. Two bodies of the same mass but different shapes will have the same thermal capacity.

Option 3 states that the thermal capacity depends on the density of the body. However, density is a measure of mass per unit volume, so it indirectly relates to the mass. Therefore, the direct factor affecting thermal capacity is the mass, not the density.

Option 4 suggests that the thermal capacity depends on the mass, shape, and temperature of the body. While the temperature does play a role in the transfer of heat, it does not influence the thermal capacity itself. The thermal capacity of a body is determined by its mass, regardless of its shape or temperature.

Therefore, the correct answer is option 1, as the thermal capacity of a body depends on its mass only.