A. Compared with diesel oil and gasoline, liquefied petroleum gas is a clean fuel, and the tail gas emitted by cars using this fuel is less polluted. The option statement is correct and in line with the meaning of the question.

B, solar energy is a kind of renewable energy, it is inexhaustible, and it is a new type of energy. The option is wrong, which does not meet the meaning of the question;

C, global communication can be realized by using three synchronous satellites, and the option is incorrectly stated, which does not meet the meaning of the question;

D, plastic is an insulating material, silver is a conductor, and the option is incorrectly stated, which does not meet the meaning of the question;

So choose a.