Rearrange the following parts in the correct sequence to make a meaningful sentence.

(A) are inborn but our (B) constituents of flavor, are learned (C) our responses to basic tastes (D) perceptions of smells, the main

The correct option is (C), (A), (D), (B).

To arrange the parts into a meaningful sentence, we can analyze the grammatical connections and logical flow between them:
1. Identifying the Subject of the Sentence: Part (C), "our responses to basic tastes", introduces a clear plural subject that requires a plural verb.
2. Connecting Subject and Verb: Part (A) begins with the plural verb "are" in "are inborn but our". This connects perfectly with (C) to form "our responses to basic tastes are inborn but our...". The conjunction "but" indicates a contrast is coming, and the possessive pronoun "our" signals that another noun phrase will follow.
3. Continuing the Contrast: Part (D), "perceptions of smells, the main", provides the contrasting noun phrase ("perceptions of smells") to match "responses to basic tastes". The phrase "the main" at the end of Part (D) prepares us for a describing noun phrase (appositive).
4. Completing the Sentence: Part (B), "constituents of flavor, are learned", completes the description ("the main constituents of flavor") and provides the verb phrase ("are learned") to finish the contrast initiated by "but".

By joining the parts in the sequence (C) ⇒ (A) ⇒ (D) ⇒ (B), we get the complete, grammatically correct, and coherent sentence:
"Our responses to basic tastes are inborn but our perceptions of smells, the main constituents of flavor, are learned."