Which is the true statement about the synapses in the spinal cord in the stretch reflex?
 sensory nuerons synapse with motor nuerons interneurons to excite the extrafusal fibers of the stretched muscle
 internuerons make inhibitory synapses with neurons that prevent contraction of the antagonist muscle
 the antagonist muscle is activated by increased frequency stimuli
 Polysynaptic intemeurons first synapse with higher brain centers