The T tubules store Ca2 . provide a means of rapidly transmitting the action potential from the surface into the central portions of the muscle fiber. store ATP. run longitudinally between the myofibrils. have expanded lateral sacs.

provide a means of rapidly transmitting the action potential from the surface into the central portions of the muscle fiber

Explanation:

T-tubules or Transverse tubules are the tube-like structures present in the muscle fibers.

The T tubules are formed by the modification in the plasma membrane of the cell and therefore arise from the surface of the muscle cell.  The T tubules then pass through the muscle and enter the inner core of the muscle that is near to the sarcoplasmic reticulum.

The main function of the T tubules is to carry forward the action potential from the synaptic junction to the muscle where it triggers the release of the calcium from the muscle.

Thus, the selected option is correct.

1: most common garden plants prefer loam — soils with a balance of different-sized mineral particles (approximately 40% sand, 40% silt, and 20% clay) with ample organic matter and pore space. however, some plants grow better in sandy soils, while others are well-adapted to clay soils.

2: available water capacity is the maximum amount of plant available water a soil can provide. it is an indicator of a soil's ability to retain water and make it sufficiently available for plant use. available water capacity is the water held in soil between its field capacity and permanent wilting point.

3: it is the same for all living things (plants and animals). it also includes very tiny organisms that our eyes cannot see. they are known as microorganisms, and include viruses, bacteria and fungi.