Systole in the heart occurs following the increase in cytosolic calcium that occurs with RyR channel opening. This calcium binds to the N-lobe of Troponin-C which in turn binds the switch peptide of troponin-I. This causes ______.

a. The C-lobe of Troponin-C
b. The inhibitory peptide of troponin-I to release inhibition of tropomyosin movement.
c. The C-lobe of Calmodulin
d. The N-lobe of Troponin-C
e. Tropomyosin