It’s the that caused the big forest fire. A young man dropped it carelessly at picnic.A.

问题补充：

It’s the that caused the big forest fire. A young man dropped it carelessly at picnic.

A. cigarette end

B. electric light

C. lightning

D. thunder

答案：

(答案→)A. cigarette end

B. electric light

C. lightning

D. thunder

解析：根据上下文的内容可知答案为A