A Match is a formal contest in which two or more persons or teams compete. It is often part of a tournament but can also exist on its own.
The Tournament consists of multiple matches between contestants. There is usually a large number of contestants in a tournament. Because of this, a tournament is usually divided into various matches, each involving some of the competitors.
You didn't include the answer choices, but a question with the same wording popped up on the quiz I just took and the answer for me was B : They suspect something strange may be going on.
