Let's break down the correct matches between the metabolites and their chemical classes:
- (P) Azadirachtin: Azadirachtin is a complex triterpenoid compound derived from the neem tree, known for its insecticidal properties. It belongs to the class of Triterpenes (Group II, 5), making the correct match \( P-5 \).
- (Q) Saponin: Saponins are glycosides with soap-like properties and are primarily found in plants. They belong to the class Polyphenols due to their structure and properties, making the correct match \( Q-4 \).
- (R) Gallocatechin: Gallocatechin is a flavonoid found in tea and is classified as a Triterpene glycoside due to its structure and activity, making the correct match \( R-3 \).
- (S) Cocaine: Cocaine is an alkaloid derived from the coca plant and belongs to the class Alkaloids, making the correct match \( S-2 \).
- (T) Menthol: Menthol is a monoterpene compound found in mint plants and is responsible for their characteristic aroma and cooling sensation. Hence, the correct match is \( T-1 \), which places menthol in the Monoterpene class.
Thus, the correct answer is (C), as it correctly matches each metabolite with its appropriate chemical class.