Why Is the Opiate Morphine Likely to Be Administered After

Why is the opiate morphine likely to be administered after major surgery?

A) To prevent anxiety and fear from blocking the healing process.
B) To create a strong euphoric rush, so that the patient becomes much easier to work with.
C) To alleviate pain.
D) Because it is known as "the plant of joy" and research shows that happy people heal more quickly.