All highly trained pilots avoid icing zones. Captain L is highly trained. Therefore L avoids icing zones. Logically:
AInvalid: undistributed middle.
BInvalid: affirming consequent.
CInvalid: denying antecedent.
DValid by syllogism.
Answer & Solution
Correct answer: D. Valid by syllogism.
1. All A do X; L is A; therefore L does X. 2. Classic modus ponens.
_Source: 501-GMAT-Questions Ch 2 Critical Reasoning_