he ____a soldier for three years.now, he works with an international company

题目

he ____a soldier for three years.now, he works with an international company
A was
B had been
C would be
D has been
答案是a,但我认为是b
谁能帮我解答下

答案

我觉得应该选A
说一下原因吧:这句话的意思是在过去他当过三年的兵,现在他在一家国际公司上班,前句是表示过去的动作所以是用一般过去时he was
至于你说的B选项had been 是过去完成时的表达,是过去的过去才用,所以不对喽