— Bill is ill. Do you know what's wrong with lum?            

—Poor boy. His illness is the_________of eating unhealthy food.     [ ]

A. result

B. cause

C. reason

D. end

男，30岁，半年前上腹部曾受钝挫伤。2个月前上腹部出现肿物，近来常有呕吐，但无腹痛及发热。检查：上腹部有巨大囊性肿物，无压痛，诊断为假性胰腺囊肿，最好的治疗方法是（）

A.继续观察

B.穿刺抽吸囊肿内容物

C.手术切除囊肿

D.囊肿外引流术

E.囊肿内引流术