Answer: D. to avoid disapproval for challenging Puritan authority.
One of the possible reasons why Bradstreet would end her poems with a confirmation of her belief in the afterlife is that she did not want her views to be disapproved. Bradstreet was a Puritan, and although she sometimes produced literature that was critical of Puritan values, she did not want to separate herself from the religion. Therefore, restating her values could have been a way in which she could avoid disapproval and scrutiny.