Answer:
The correct answer is - The diaphragm.
Step-by-step explanation:
If there is a response to stimulation if a bodily tissue or organ becomes active and those of the autonomic system involves two neurons, not single neurons like motor pathways of the somatic nervous system.
In this case, the diaphragm is the organ that gets the signal in order to correct or adjust the rate of contraction in response to changes in pH level, Hence, the diaphragm is the organ that is the effector in this case.