Under what conditions would the use of a Class C fire extinguisher be preferable to a Class A extinguisher? C类火灾灭火器比A类灭火器更适用于以下哪一种情况？（）

A、A .When the fire involves paper products当火灾和纸制品有关时

B、B .When the fire is caused by flammable products当火灾由易燃物造成

C、C .When the fire involves electrical equipment当火灾和电器设备有关时

D、D .When the fire is in an enclosed area当火灾发生在一个封闭空间内