When marriott decided to improve the quality of service it offered its customers, it asked special corporate guests to comment on the good and bad issues of their stay and also to tell what the competition is doing that is better than marriott. the marriott acted accordingly. in other words, it used

benchmarking                                

Explanation:

Benchmarking in a company is a practice of comparing the different business processes as well as performance metrics compared to industry bests and the best practices performed from the other companies. It is the process of evaluating one's performance and service with the standards.

In the context, when Marriott asks its customers to review and comment on their services and also inform them about the practices performed by their competitors, it is trying to benchmark their company.

answer; all of the above are correct;