Answer:
At the moment of writing a literary analysis essay on Shakespeare's Macbeth. The following is a reliable source of information on the topic:
4) a literary critic's analysis of the characters and their contrasts in the play
Step-by-step explanation:
Reliability is gained over validity and confirmability. These two aspects are earned after an educational institution provides a credential to a certain individual to prove he or she earned a scientific education to perform problem-solving in its area. However, those institutions also follow other institutions' guidelines that establish the way knowledge is obtained. Therefore, only a critic's analysis would be a reliable source. Because it would be the only one to hold a credential provided by a recognized institution.