Which weather element directly influences the minimums used to authorize takeoff and landing on the A321?

• A. Crosswinds
• B. Windshear
• C. Approach minimums (ILS CAT I vs II/III)
• D. Visibility

Answer: (C)

The key idea is that whether you can authorize takeoff or landing is controlled by the published instrument approach minima for the procedure you intend to fly. Those minima specify the weather thresholds, such as visibility and decision altitude/height, for each approach category (for example ILS Cat I versus Cat II/III). The A321 must meet the appropriate minima to proceed; Cat I offers higher minimums, while Cat II/III allow lower ones, reflecting the level of navigation and lighting available. This is why the option describing approach minimums is the best answer—it directly defines the weather thresholds used to authorize the operation. Crosswinds and windshear are important operational considerations, and visibility is a component of the minima, but the mechanism that determines whether takeoff or landing is authorized is the approach minimums tied to the approach category.