Mismatched premises. The stimulus gives a conditional relationship with two necessary conditions, which are each independently sufficient for some other thing. (A) gives a conditional relationship with two necessary conditions (executive position→ university diploma and sales experience), but instead of saying that the necessary conditions are each independently sufficient for some other thing, (A) introduces a new conditional relationship (6+ months and /sales experience→ university diploma).

Mismatched conclusion. The conclusion of the stimulus is the contrapositive of a conditional chain given in the premises; the conclusion of (B) is not the contrapositive of a conditional chain. The contrapositive of the conditional chain in (B) would be “/something better to do→ /elected president.” However, (B) makes the invalid conclusion of “something better to do→/elected president,” so (B) does not match the structure of the stimulus.

The diagram for (C) matches the diagram of the stimulus:

Mismatched premises. The stimulus gives a conditional relationship with two necessary conditions, which are each independently sufficient for some other thing. (A) gives a conditional relationship with two necessary conditions, but then says that one of those necessary conditions is sufficient for something else (highway→ /beautiful scenery).

Mismatched conclusion. The conclusion of the stimulus is the contrapositive of a conditional chain given in the premises; the conclusion of (E) is not the contrapositive of a conditional chain. The contrapositive of the conditional chain in (E) would be “/coupon→ /discount.” However, (E) makes the invalid conclusion of “/discount→/coupon,” which is a confusion of the sufficient and necessary conditions.