Students regularly seek out professor guillory to advise them. she has an exceptional manner, and students are confident in her and trust her advice. for these students, is the most important of the five service quality dimensions.

Assurance

Explanation:

Five service quality are the characteristics that are used for measuring the quality of service through evaluating responsiveness, assurance, tangibility, empathy and reliability.

According to the question, students are more focused on assurance factor out of all the service quality factors because they expect a secure advise.  

The quality of assurance imparts trust and confidence in the students and make them believe that the advise given by Professor Guillory is good .