Select the most appropriate option to fill in the blank.
Either side of the road ______ lined by toy shops.

Correct option is A

The correct option to fill in the blank is (a) "is."
· "Either side of the road" refers to a singular entity, even though it implies two sides. Therefore, we need a singular verb.
· "Lined" is the past participle of the verb "to line," and in this sentence, it is used in the passive voice.
· In the present simple tense of the passive voice with a singular subject, the auxiliary verb is "is."
Therefore, "is" is the most accurate and grammatically correct way to complete the sentence.
The other options are incorrect because:
· (b) "has" is singular but used in the present perfect tense, which doesn't fit the context of the sentence.
· (c) "have" is plural and cannot be used with a singular subject.
· (d) "are" is plural and also used in the present simple tense, but with a plural subject, which doesn't apply here.