The answer is A. It should be included under "Employment History"
Explanation:
Volunteer experience is considered as a job in which people do not receive economic compensation. Even though it is a non-paid job, those who enrolled in a volunteer experience have to do tasks that are not that easy that is why it is considered as employment and should be included in this history. One example of this could be teaching English in under-developed countries for free.
Methinks already from this chemic flame, I see a city of more precious mould: Rich as the town which gives the Indies name, With silver paved, and all divine with gold.
