Answer:
B. Nuclear to Electrical
Step-by-step explanation:
Atoms are split at power plants to create electricity. The energy conversion in this process is from nuclear to electrical energy. 
- When atoms are split, nuclear energy is released. 
- Some part of the mass of the atom is converted to energy. 
- The nuclear energy released is expressed as heat energy. 
- This energy is used to heat water in boilers when produces steam that are used to drive the movement of turbines. 
- This in turn generates electricity.