Answer:
The storage of calcium ions. (Ans. A)
Step-by-step explanation:
T-tubule are the extension part of the cell membrane (which contains a large number of transporters, pumps & ion channels) which penetrate the central skeletal & cardiac muscle cell.
The primary function of the transverse tubule (T-tubule) is to storage and providing calcium ions for muscles contraction. T-tubule allows rapid movement of the action potential, & play a very important role in releasing cellular calcium concentration. Through this process, transverse tubule allows heart muscle cell contract forcefully by calcium (synchronizing) release from the cell.