Answer: Unconditional response
Explanation:
Sonya had leukemia since childhood and because of this she had to undergo chemotherapy for a numerous times.
The side effect of the chemotherapy is that she felt nausea for numerous times because of chemotherapy.
After a year of treatment even the waiting made her feel the same because of the unconditioned response by her brain.
This can be defined as an involuntary reaction which is produced by the brain in case of the similar conditions. This is a unconditional response produced due to unconditioned stimuli.