According to the author energy security can only be achieved by ______.

A．People have little confidence in nuclear power for the potential disaster of nuclear accidents.
B．People think it important to exercise strict monitoring and effective management of the existing plants.
C．People believe the best way to avoid nuclear disaster is to shut down all the nuclear power stations.
D．People agree to prohibit the existing nuclear plants from running to the end of their useful lives.

A．illustrate the ways to repair his bicycle
B．discuss the problems of his bicycle
C．tell us how to solve a problem
D．show us how to analyse a problem