Depression

[chopra]

Pl. Explain

[dilipcrangan]

Between D and E, D looks good to me

[rayarya]

Agree.... difficult to decide.. go with D

[adiknish]

I'm going against the grain here...but I think A is fine.

It seems parallel and the verb tenses seem correct.

having been prescribed...or having been taken

Let's shorten the sentence

Some patients may have recieved inadequate treatment, for example having been prescribed... or having been taken....

Also, the word may implies that it could have happened IF...not when

What's the Official Answer?

[safazal]

A is good and parallel.

[hangptt]

what about C?

[chopra]

Official Answer is A.

I picked D too but now i think Adiknish is right. A seems to be parallel. D uses been at one place and were at other.