Muscle Contraction Is Triggered

Multiple Choice

Muscle contraction is triggered

A) in response to an increase in the cytoplasmic Ca²⁺ concentration.
B) in response to a decrease in the cytoplasmic Ca²⁺ concentration.
C) in response to an increase in the cytoplasmic cAMP concentration.
D) in response to a decrease in the cytoplasmic cAMP concentration.
E) in response to an increase in the cytoplasmic titin concentration.