when the book was published, he ___ the most popular writer of the time.A became B had become
问题描述：
when the book was published, he ___ the most popular writer of the time.A became B had become
但是英语老是说是B,我都搞糊涂了
答
选A became
B had become是过去完成时 表示过去的过去如果用这个 就表示在书出版以前 他就是最受欢迎的作家了