Cardiac Muscle Can Increase Its Strength of Contraction by All

Multiple Choice

Cardiac muscle can increase its strength of contraction by all of the following EXCEPT

A) Stretch, by increasing the sensitivity of the myofilaments to Ca²⁺
B) Increasing the size of the Ca²⁺ transients by phosphorylation of phospholamban
C) Increasing recruitment of cardiomyocytes
D) Increasing the size of the Ca²⁺ transients by phosphorylation of DHPR
E) Increasing the size of the Ca²⁺ transients by phosphorylation of RyR2