Recommendation systems must balance exploitation—suggesting items similar to those a user has already selected—with exploration, which tests less predictable suggestions to learn more about the user's preferences. For example, a music app might occasionally recommend jazz to a listener who usually chooses rock; the listener's response gives the app information that another rock recommendation would not. Although exploration can improve future recommendations, using it too often may make suggestions feel irrelevant. Designers therefore adjust how much a system explores rather than relying exclusively on either approach.
Which choice best describes how the underlined sentence contributes to the text?