I think it’s a. 12
Explanation:if it’s wrong kill me
“Tell me if I’m right”
<span>The types of effects that the surgery had on the rats were documented with their bar-pressing behavior. The differences and changes from the injections effected the rats in certain ways. The location of the injection and which types that was more pleasurable for the rat is something that needs further investigation.</span>
The answer to this question is b carpel that's the answer