Answer:
The correct match of the given terms with their purpose would be as follows:
1). "One world...voluntourism" - C. Provide expert testimony to refute the counterclaim's point.
2). "If you...voluntourism" - A. State the claim
3). "Serve...mentor" - B. Provide examples that support the claim
4). "Studies show that volunteering and forming lasting relationships with those you help have a positive impact on your physical and emotional health." - E. Present a point to support the claim
5). "In fact...reduced" - D. Provide facts to support a point
The various details and the function they are serving would be correctly matched as provided above.
The main claim of the work is to inform the readers that a true experience can be gained through several other ways apart from voluntourism.
This is followed by the illustrations that back the claim. A Counterclaim is refuted post this and validating evidence to rebut it.
Lastly, the main point is backed by the facts and recalled to give an impression into readers' mind.