D. Ability to read
Hope this helped
Because there is nothing to hear
Answer:
Columnar epithelial cells are elongated and column-shaped and have a height of at least four times their width. Their nuclei are elongated and are usually located near the base of the cells. Columnar epithelium forms the lining of the stomach and intestines
Explanation:
Epithelium - Wikipedia
Hope this helps : )
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.
