D. The entire paragraph was amazing, but sentence D seems a tad out of place. It is relevant to the topic though so it would probably serve a better purpose elsewhere in the paragraph.
The paragraph contains sentences that wander from the main topic.
The heading of the paragraph states that volunteering on a regular basis benefits one´s general physical health and supposedly the content of the paragraph should exemplify and detail some issues that support the main topic.
Nevertheless,many sentences detail situations not directly related with the main idea,e.g. examples of easy ways to integrate exercise into a daily routine, or how to combine minimal movement actions with some type of physical activity.
Reversal of fortune from good to bad. Tragedy is a play that deals with tragic events that leads to the downfall or demise of the main character resulting to an unhappy ending.