The taxpayers unmarried child lived with him or her all year and was 18 years old at the end of the year. The child did not provide more than half of their own support and does not meet the tests to be a qualifying child of anyone else. As a result, which of the following is true?

A. The child is the taxpayers qualifying child

B. Because the child is single, he or she is also a qualifying person for head of household purposes

C. The child is not the taxpayers qualifying child

D. A and B