Final answer:
In the warm sector of maritime tropical air during a summer afternoon in Western Europe, hazy conditions are to be expected due to the accumulation of moisture or dust particles.
Step-by-step explanation:
The question asks about the typical visibility conditions in the warm sector of maritime tropical air during a summer afternoon in Western Europe. A warm sector is the area of a weather front that is bounded by the cold and warm front, where warm and moist air from the tropics is predominant.
This scenario in Western Europe during summer often leads to d. Hazy conditions, due to the high humidity and temperature leading to the formation of haze, which is an accumulation of very fine moisture or dust particles that can reduce visibility.