Personal Long Letter (GMATCLUB Knewton question)

[showbiz]

The idea behind the Personal Long Letter campaign is that a single impassioned constituent may sway a lawmaker's opinion, whereas a half-dozen banded together only causes him alarm.

a) a half-dozen banded together only causes him alarm
b) only alarm is caused by a half-dozen banded together
c) only alarm has been caused by a half-dozen banded together
d) a half-dozen banded together only cause him alarm
e) a half-dozen have caused him only alarm when banded together

OA: A

[showbiz]

Exlpaination Given:

The noun half-dozen, though it refers to a collection of six discrete things or people, is grammatically singular. Any verbs that take it as their antecedent, then, must also be singular. This sentence also tests correct verb form, which should be simple present tense because the sentence refers to facts that are generally true. The sentence is correct as written.

The noun half-dozen agrees with the verb causes, and the correct simple present tense is used to describe facts generally believed to be true.
Verb tense is correct in this option, but the phrasing of the sentence is wordy and awkward.
The verb form has been caused unnecessarily uses past perfect, and the word order is awkward.
Cause does not agree with the singular a half-dozen.
This option is awkward and wordy.
The correct answer is A.

My question is, shouldn't there be the noun with with the pronoun "him" should be associated with? It seems ambiguous here.

[pesfunk]

Perfect explanation..it is A.

Exlpaination Given:

The noun half-dozen, though it refers to a collection of six discrete things or people, is grammatically singular. Any verbs that take it as their antecedent, then, must also be singular. This sentence also tests correct verb form, which should be simple present tense because the sentence refers to facts that are generally true. The sentence is correct as written.

The noun half-dozen agrees with the verb causes, and the correct simple present tense is used to describe facts generally believed to be true.
Verb tense is correct in this option, but the phrasing of the sentence is wordy and awkward.
The verb form has been caused unnecessarily uses past perfect, and the word order is awkward.
Cause does not agree with the singular a half-dozen.
This option is awkward and wordy.
The correct answer is A.

My question is, shouldn't there be the noun with with the pronoun "him" should be associated with? It seems ambiguous here.