Final answer:
Skeletal muscle cells have organelles called sarcoplasmic reticulum (SR) that contain large stores of calcium ions. The calcium is released during muscle contraction and then pumped back into the SR as the muscle relaxes.
Step-by-step explanation:
Compartmentation at the intracellular level refers to the separation of different components within a cell. An example of compartmentation at the intracellular level is C) Skeletal muscle cells have organelles called sarcoplasmic reticulum (SR) that contain large stores of calcium ions. The calcium is released during muscle contraction and then pumped back into the SR as the muscle relaxes. The sarcoplasmic reticulum acts as a compartment within the muscle cell, storing and releasing calcium ions for muscle contraction.