A. Guinea savanna → Sudan savanna → tropical rain forest → Sahel savanna → estuarine
B. Estuarine → tropical rain forest → guinea savanna → Sahel savanna
C. Sahel savanna → tropical rain forest → estuarine → guinea savanna
D. Sahel savanna → Sudan savanna → guinea savanna → tropical rain forest → estuarine
Correct Answer:
Option D – Sahel savanna → Sudan savanna → guinea savanna → tropical rain forest → estuarine