Answer:
D. Mineral oil
Explanation:
Warm mineral oil can be used in removing the bee from his ear. By bending the head of the boy so that the ear that has the bee in it faces upward, a little amount of mineral oil can be poured into the ear to suffocate and flush out the bee.
Tweezers can only be used for objects that is visible and can be picked, and not for insects. Using hair pin will only worsen the situation and would be ineffective, giving rise to further complications.