Concept: This question tests your knowledge of the characteristic floral features of the family Liliaceae, a monocot family, often represented by plants like onion and lily.

Why (C) is correct: Liliaceae is characterized by trimerous flowers (floral parts in multiples of three), meaning six tepals (3+3), six stamens (3+3), and a tricarpellary ovary. The flowers are typically actinomorphic (radially symmetrical) and bisexual. The stamens are polyandrous (free). The ovary is superior, trilocular, and exhibits axile placentation.

Why other options are wrong:

A) Zygomorphic flowers are not characteristic of Liliaceae; they are actinomorphic. Bilocular ovary is incorrect; it's trilocular.

B) Tetramerous flowers are not found in Liliaceae (they are trimerous). Polyphyllous (free perianth parts) is incorrect; they are often united (gamophyllous) or free but not polyphyllous in the sense of separate leaves. Unilocular ovary is incorrect.

D) Zygomorphic flowers are incorrect. Inferior ovary is incorrect; it's superior. Marginal placentation is incorrect; it's axile.

E) Unisexual flowers are incorrect; they are bisexual. Inferior ovary is incorrect; it's superior.

NEET Tip / Mnemonic: For Liliaceae, remember "3-3-3": 3 sepals + 3 petals (often indistinguishable, hence 6 tepals), 3+3 stamens, and a 3-chambered (trilocular) ovary. Also, remember it's a monocot family, so trimerous is a key feature.

Correct Answer: (C)