Answer: C A B
C) activation of a sensory receptor
A) information processing in the CNS Â
B) signaling by an efferent PNS neuron Â
SYNAPSE AT THE EFFECTORS for refection action.
Explanation:
the arrival of the action potential at the effector  initiate contraction of muscles and secretion  by glands  in response to stimulus of sighting a predator.
this involves the flow of action potential from the presynaptic neuron to the synaptic cleft where neurotransmitters, (from calcium ions fusion to the membranes) ,binds with the receptors on the muscles and post synaptic  neuron  to imitate synaptic reaction for action potential
this brings response  in animal to run and hold still at the sight of the predator.