The error made by the author here is a simple reversal of sufficient and necessary conditions. However, the awkward wording of this passage makes it difficult to follow.
"People who have never been asked to do more than they can easily do (NADM) are people who never do all they can (NDAC)."
NADM - -> NDAC
Alex has not done all he can (NDAC), so no one has ever asked him to do more (NADM).
NDAC - -> NADM
Do you see how the conditions have been reversed? The author takes the necessary condition and uses it to conclude the sufficient. This is not valid. The necessary condition does not guarantee the sufficient condition.
So, which answer choice makes the same error?
A. "Anybody who has a dog (HD) knows the true value of companionship (KTV)." HD - -> KTV
Alicia knows the true value of companionship (KTV), therefore she has a dog (HD). KTV - -> HD
The author has used the necessary condition to conclude the sufficient. Not valid. There may be many other ways to learn the true value of companionship. It never says that having a dog is the only way.
