Question

which part of a reflex arc connects the effector to the spinal cord

A) sensory neuron
b) motor neuron
c) receptor
d) reflexor

Answer 1

...This is higher level bio than what I'm used to dealing with. But you seem to be needing this answered. After looking it up, the overwhelming tendency is for the answer to be B. I hate to just give you an answer, but I don't know much on the given subject.

Answer 2

Effector can be a muscle or a gland
if it is a muscle, it will lead to contraction of a muscle
if it is a gland, it will lead to releasing of the content of gland into wherever
now reflex arc is all about nerves
the nerve that takes info into spinal cord (e.g. too hot) is a sensory nerve or afferent nerve
now once it reaches the spinal cord, it synapses with other nerve that will respond to this situation, example ill bring is u touching something hot, hot is the sensory info taken to spinal cord now your response will be ' remove your hand from this hot object ' to do this you need your muscles, so muscles will be you effector, now the nerve controlling muscle contraction is motor nerve or efferent nerve
so connection between effector and spinal cord is through motor neutons/nerve