In option (a), plural noun 'guests' is followed by the singular determiner 'each' and thus the sentence is erroneous. Instead, the singular noun 'guest' is to be used. Other sentences are grammatically correct and meaningful.
Hence, the correct answer is option (a).
Note:
Subject-Verb Agreement: Matching up singular or plural subjects with singular or plural forms of a verb is part of the process called agreement. This can be understood better by the examples given: - "She likes cooking." [singular subject and verb] -- "They like to cook vegetables." [plural subject and verb]
Determiner: A modifying word that determines the kind of reference a noun or noun group has, for example, 'a', 'the', 'every', 'much', 'many', etc.
Study Notes
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