(A) The center has a self-interested motive to attract new volunteers.
The passage is from a newsletter for volunteers, so the center may indeed want more volunteers.
However, the argument is about whether volunteering improves well-being, not about the center’s motives.
Incorrect.
(B) It interprets “well-being” as including the factors of social and economic resources, mental outlook, physical health, and overall functioning.
The passage defines well-being broadly but does not make an error by doing so.
The problem isn’t in the definition—it’s in assuming that volunteering causes these benefits.
Incorrect.
(C) Some of those who do not volunteer might be older than some volunteers and so could not be considered their peers.
Even if some non-volunteers are older, that does not explain why volunteers seem healthier.
Age difference is not the key issue—the issue is whether volunteering causes better health or if healthier people just tend to volunteer.
Incorrect.
(D) Growing older might not necessarily result in a change in mental outlook.
This does not address the argument’s main flaw.
Even if mental outlook did change with age, the question remains: Did volunteering cause better mental outlook, or were healthier people more likely to volunteer?
Incorrect.
(E) Those with better resources, health, outlook, and functioning are more able to work as volunteers.
This directly weakens the argument.
If healthier, wealthier, and more socially active people are simply more likely to volunteer, then volunteering is not necessarily the cause of their well-being.
Correct...