The Major Processes That Heat the Interiors of the Terrestrial

The major processes that heat the interiors of the terrestrial worlds are

A) (1) Heat deposited as the planets were built from planetesimals;(2) heat of accretion;(3) heat that came from the gravitational potential energy of incoming planetesimals.
B) (1) Heat of accretion;(2) heat from convection;(3) heat from thermal radiation.
C) (1) Heat deposited as the planets were built from planetesimals;(2) heat deposited as the planets underwent differentiation;(3) heat released by radioactive decay.
D) (1) Volcanism;(2) tectonics;(3) erosion.