Because Mr. Dunham always wanted an opportunity to work with animals, he decided to volunteer at his local animal rescue shelter on Saturdays. However, there is a requirement that all part-time volunteers work at least one evening a week. He's not sure that he can meet this obligation because he often works late at his job. He hopes that the shelter might make an exception in his case. Underline words - A) opportunity, B) requirement, C) obligation, D)exception​