Concept:The harmattan is a dry, dusty wind from the Sahara Desert that dominates West Africa during the dry season.
Explanation:In West Africa, the dry season generally spans from November to March.
The harmattan blows most strongly and frequently within this dry period.
Among the given choices, November to January is the closest match to the peak harmattan months.
The other periods, August to October and May to July, fall within the rainy season.
February to April includes the late dry season, but the core harmattan period is better represented by November to January.
Answer:C. November to January