- 
					 Fusion reaction takes place at high temperature because
 
- 
                        
- nuclei break up at high temperature
 - atoms get ionised at high temperature
 - kinetic energy is high enough to overcome the coulomb repulsion between nuclei
 - molecules break up at high temperature
 
 
Correct Option: C
When the coulomb repulsion between the nuclei is overcome then nuclear fusion reaction takes place. This is possible when temperature is too high.