Final answer:
The simple sentence from the choices is 'Tal, Naama, and Hamsini enjoyed their book club.', as it has a single main clause with a compound subject sharing one main verb.
Step-by-step explanation:
The simple sentence from the options provided is: a. Tal, Naama, and Hamsini enjoyed their book club. A simple sentence contains one main clause with a single subject and predicate.
Despite having three subjects (Tal, Naama, and Hamsini), they are part of a single compound subject and share one main verb, which makes it a simple sentence. The other sentences (b and c) contain conjunctions ('and', 'but') which connect two independent clauses, making them compound sentences.