This is a Tamil wordplay question. 'Kaapu' (pronounced like 'capu') refers to a hand protection/gauntlet that can be used as a weapon in fight scenes. The options play on similar-sounding words - 'maapu', 'aapu', 'kaapu', 'soapu' - with 'kaapu' being the correct Tamil word for protective hand gear/armguard used as a weapon in cinema fight scenes.