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