Which subunits compose troponin and their roles?

Which subunits compose troponin and their roles?

• A. Troponin A binds Ca2+; Troponin B inhibits cross-bridge; Troponin D binds actin.
• B. Troponin C binds tropomyosin to block binding sites.
• C. Troponin C binds Ca2+; Troponin I inhibits actin-myosin interaction when Ca2+ is low; Troponin T binds tropomyosin to actin.
• D. Troponin C inhibits actin; Troponin I binds Ca2+; Troponin T displaces tropomyosin.

Answer: (C)