Sentence Correction

could someone please explain this?

Let's have a look at options.
B --> Changing active sentence to passive. So Incorrect. Also, it suggests the sentence to have "but proved unpopular". What was unpopular? Even "dollars" which is considered the subject doesnt match with singular "it" in the later sentence.
C --> It says that dollars were unpopular. Then "it looked ... like a quarter" is singular which doesnt match with plural word "dollars".
D --> Same as C.
E --> Same as C.

thank you

only A contains coin which proved unpopular....

so A.

B has coins.....it issue....

the 'it' (in the not underlined portion of the question) forces us to choose A ; in other choices 'it' can't refer to anything.