Select the statement that is most correct. select one:
a. the cell bodies of afferent ganglia are located in the spinal cord.
b. ganglia associated with afferent nerve fibers contain cell bodies of sensory neurons.
c. ganglia are collections of neuron cell bodies in the spinal cord that are associated with efferent fibers.
d. the dorsal root ganglion is a motor-only structure.

b. Ganglia associated with afferent nerve fibers contain cell bodies of sensory neurons.

Explanation:

4, 3 5, 1, 2.

Explanation:

The events of muscle contraction begins from the presynaptic neuron, which cause the influx of Ca+, and the release of acetycholine neurotransmitter  into the synaptic cleft.

The Ach, binds with the receptors in the sarcolemma, leading to opening of Ligand gated Na+ channels. Therefore Na+diffuses in, causing depolarization, and propagation of action potential along the sarcolemma  spreading to the  T-tubules.

This is followed by opening of Calcium channels leading  exist of Ca+ from the sarcoplasmic reticulum.

The Calcium binds with the troponin, and  Tropomysoin exposed the myosin binding sites  on the actin filament.Thus cross-bridge is formed by the myosin head  with thin filaments which   shortened the sarcomere, leading to contraction of muscle fibres.