As you reach for a rose, you unexpectedly feel the painful poke of a thorn. you quickly withdraw your hand. which part of this process is accomplished mainly by the central nervous system?

For the answer to the question above, I think the answers are

"The stimuli input"
it is the stimuli that are perceived by our senses like smell, sight, touch, taste, and hearing.

"Integration" and "motor output"
which is the function of three inputs – sensory, cognitive, and intrinsic.

That would be a working theory.