A sentence refers to the pair of words which is complete in itself. In other words, a sentence contains a subject and a predicate or it may contain a main clause and one or more subordinate clauses to convey a command, exclamation, question or statement.
<em>
Subject</em> refers to the thing or person that is being talked about or described.
Therefore, word which represents the subject in the sentence is 'I', who is the doer of the action.
Answer:
He understands Stanton’s frustration with her own capabilities, but he still believes she can succeed.
hope this helps im working on this lesson now !!