Answer: Users.
Step-by-step explanation:
There are 7 positions in the Buyer Decision Process which includes the Initiators, the buyers, decision makers, influencers, Users and Gatekeepers.
The Users are the finally people who actually use the product and their opinion matters. They are usually consulted on how to make a product better in the post-evaluation process.
Kate as a sales representative arranged to meet students and got their feedback on textbooks with the aim of using their feedback to make their textbooks better. This would signify that the students play a USER role in the buying centre and their opinion is being used to learn to make a product better. Also, the company sells textbooks and textbooks are usually for students.