The answer is option C: Analysts can only speak analytically.
Nouns are words (other than pronouns) that identify or name things, places or people. Adverbs modify adjectives, verbs or other adverbs, and indicate time, place, manner, degree or circumstance.
In sentence C, "Analysts" is a noun and "analytically" is an adverb. The rest of the statements contain nouns and verbs.
