Concept:Basement complex rocks are ancient crystalline rocks that form the foundation of the Earth's crust in many regions.Explanation:In West African geography, the basement complex consists of very old rocks that have been folded, metamorphosed, and intruded by granites.These ancient rocks are commonly classified together as older granite because they predate the younger intrusive granite rocks found in some areas.This distinguishes them from sedimentary and volcanic formations.Answer:B. older granite