D. A record of all the physical activity you complete in one week.
Explanation:
A "Fitness Log" allows you to keep track of your workout or exercise. Therefore, it is <em><u>a record of the different workout you've managed to complete within a time frame</u></em>. It gives you several information such as the<em> type of workout you've completed, its duration and the time of the day it was performed</em>. This makes a person motivated to exercise because he can see his progress. He may also include <em>his mood before and after workout</em> in order to become more mindful in exercising and many other things.
