To answer this question, we need to understand the subject-verb agreement in English grammar.
In this case, the subject is "seven and five," which is a compound subject. When a compound subject is joined by "and," it is generally treated as a plural subject and requires a plural verb.
Therefore, the correct statement would be "seven and five are thirteen," as in option A. This option is correct because it follows the rule of subject-verb agreement for a compound subject.