Correct option (c) lemon
Explanation:
Lemon (Citrus sp.) belongs to family-Rutaceae, characterised by axile placentation. Argemone belongs to family-Papaveraceae, contains parietal placentation. Dianthus belongs to family-Caryophyllaceae, contains free-central placentation. Marigold belongs to family-Asteraceae, contains basal placentation.