What is the primary reason fusion is not used in power plants?

A. Fussion causes too much air pollution

2. Fission creates more energy than fussion

C. The cost of using fussion in a practical way is too expensive

D. Currently technology is unable to control the reaction.

The correct answer is D, Current technology is unable to control the reaction.

Fusion is a process when two small elements fuse together to form a large element. It is a fundamental process that occur on the Sun, in this process tremendous amount of energy is released, however its very difficult to initiate this process, as it require a large amount of energy to propagate, also once the process is initiate it becomes extremely difficult to control the process, and currently we are not able use the fusion process in the power plant.

Therefore the correct answer is Currently technology is unable to control the reaction.