A severe and long dry season is a characteristic feature of

Analyze the question: It asks which vegetation zone is marked by a severe and long dry season. Think of the Nigerian vegetation belts from south to north, and how the length of the dry season changes along them.

Explain the concept: Nigeria's vegetation zones are arranged by rainfall, which decreases as you move north:

| Zone | Rainfall | Dry season | |---|---|---| | Mangrove/Coastal swamp | Very high | Almost none | | Rainforest | High | Short | | Guinea Savanna | Moderate | Moderate (about 4-5 months) | | Sudan Savanna | Low | Long (about 6-7 months) | | Sahel Savanna | Very low (under about 600 mm) | Very long and severe (about 7-9 months) |

Solution:

• Mangrove Swamps (B): These are waterlogged and wet nearly all year, so they are ruled out.
• Guinea Savanna (D): This has a distinct dry season, but it is moderate, not the most severe.
• Sudan Savanna (C): The dry season is long, but it is less extreme than in the Sahel.
• Sahel Savanna (A): This is the northernmost belt, bordering the Sahara. It has the lowest rainfall, a very long dry season, harsh harmattan conditions, and sparse, thorny, stunted vegetation. It best fits "severe and long dry season."

Answer: A. Sahel Savanna

Tip: Remember the order from the coast northward: M-R-G-S-S (Mangrove, Rainforest, Guinea, Sudan, Sahel). The further north you go, the drier and harsher the dry season. When you see "severe," "very long dry season," or "near-desert," choose the Sahel.