Final answer:
The kind of activity an individual must do to build a specific part of fitness and gain a specific benefit is referred to as frequency.
Step-by-step explanation:
The correct answer is c. Frequency. Frequency refers to how often an individual must engage in a specific activity in order to build a specific part of fitness and gain a specific benefit. The frequency of exercise can vary depending on the individual's goals and fitness level. For example, someone looking to improve cardiovascular fitness may need to engage in aerobic activities such as running or swimming at least three to five times a week.
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