Members of Congress were surprised to learn that legislation that was passed to prevent discrimination on the basis of religious beliefs had been used by convicted felons demanding special treatment while serving terms of imprisonment.
A had been used by convicted felons demanding special treatment while serving terms of imprisonment.
B had been used by convicted felons who demanded while serving terms of imprisonment.
C was used by convicted felons who demanded special treatment while serving out their terms of imprisonment.
D was used by convicted felons demanding special treatment while serving terms of imprisonment.
E was used by felonious convicts who had demanded special treatment while serving terms of imprisonment.
This question is based on Tenses and Construction.
A vertical scan of the options gives us a choice between the past perfect tense – had been used - and the simple past tense – was used.
The other verbs in the sentence are ‘were surprised’ and ‘was passed’.
Since the action in the underlined portion does not convey an earlier action, it does not have to be in the past perfect tense. On the basis of this rule, Options A and B can be eliminated.
Option E also contains the past perfect tense – had demanded. Since this action did not take place before the other actions, this verb also does not have to be in the past perfect tense form. So, Option E can also be eliminated.
The difference between Options C and D is the difference in modifier.
Option C contains an adjective modifier that modifies the subject – convicted felons. While the subject of the modifier is appropriate, the time frame conveyed by the use of the simple past – demanded – is not. The modifier describes an action that is done by felons continually. So, a participle would be more appropriate.
Furthermore, the adverb ‘out’ is redundant. The phrase ‘serving terms of imprisonment’ is appropriate.
So, Option C can be eliminated.
Option D contains the appropriate verb and tense forms. This option also contains a participle modifier that conveys a sense of continual action. Therefore, D is the most appropriate option.