An example for X-linked recessive disorder is (C). Color Blindness
Excitation-contraction coupling refers to the series of events that begins with the excitation of the sarcolemma in response to stimulation by a neurotransmitter, and results in the release of calcium ions from the sarcoplasmic reticulum.
Hence, option D is the 1st process that starts the excitation-contraction coupling.
C. The material for it is super expensive and sometimes fragile, which sucks, but it's true.
Carbon is the basic element for living thing
