Hello. You did not enter the text to which this question is related, which makes it impossible for it to be answered. However, I will try to help you in the best possible way.
A sentence that supports a statement is a sentence that can prove that the statement is correct and true. Thus, to answer this question, you must read the text and identify the information and sentences that prove that Robert is single, that is, you need sentences that prove that he is not married, nor involved in a relationship.
