Are u guys sure E is wrong??
There is a rule that says that the past perfect tense 'had been...' should not be used unless we are mentioning two different things in the past and trying to put one before or after the other. The user od had been is unwarranted here and is the reason why D and E are ruled out.
I am quoting Princeton Review Verbal
Workbook here for your reference
The past perfect tense indicates that two things have happened
in the past, and you have to show which one happened first.
For this, you use the word had (or had been)