Problem: Which type of contraction allows a muscle to produce tension without changing the angle of a skeletal joint or moving a load?
-  A functional group of sarcomeres
 
-  All of the muscle fibers in a specific muscle
 
-  A motor neuron and the muscle fibers it innervates
 
-  The sarcomere and its associated sarcolemma
 
-  A packet of actin and myosin microfilaments