I think the answer is C, because if they are speaking clearly then people can fully understand what they are saying.
Iambic pentameter and sonnets
B. to cook
An infinitive almost always begins with “to” and is followed
by the basic form of the verb. It is usually in this form:
To + Verb = Infinitive
An infinitive is NOT a verb, so s, es, ed, or ing should not
be added to the end. Infinitives can be used as nouns, adjectives or adverbs.
According to the pattern of what an infinitive should be, “to cook” is the
infinitive of this sentence and it functions as a noun.
Swallowtail it has a s at the end of wings so no s on swallowtail
