Wrong trigger. To prove a gift is selfish, we need to know that it’s either given to benefit the giver or worth less than expected. (A) tells us the gift is expensive, while also giving us no information on whether Charles intended to benefit from the gift, so we can’t justify that it is selfish.

Wrong trigger. To prove a gift is selfish, we need to know that it’s either given to benefit the giver or worth less than expected. Offending the recipient is not one of these conditions, so we can’t prove the membership is selfish.

Wrong conclusion. We are only given necessary conditions for a gift to be generous, so we can only conclude that a gift is not generous—not that it is.

One of the necessary conditions for a gift to be generous is that it is worth more than expected. If every child receives a computer upon graduation, the gift is worth exactly as much as is expected, and fails this necessary condition.

Wrong trigger. One of the necessary conditions for a gift to be generous is that it must be intended to benefit the recipient. We know the money didn’t actually benefit his nephew, but we have no clue whether it was intended to, so we can’t conclude the gift wasn’t generous.