I dont want to mislead you, but I believe the answer is A because letter B is wrong because plants go through cellular respiration and photosynthesis, whereas animals go through cellular respiration but not photosynthesis, and for C, I've never heard of that so it doesnt seem likely.
Answer:
A living organism whose genes have been purposefully altered
Explanation:
The correct answer to the question stated above is the first option: <span>an instinctive behavior was tied to a different stimulus.
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Pavlov's experiment was a typical case of classical conditioning because an instinctive behavior was tied to a different stimulus.