Continental crust is made up of and it is compared to oceanic plates.

Continental crust is made of Silicon and aluminium light weight plates as compared to Magnesium and iron in oceanic that are heavy elements.

Explanation:

Oceanic crust is divided into three layers as

1. Semi consolidated sediments

2. Crystalline Basalt

3. Course grained Ultramafic igneous rock

Most of the oceanic floor is dotted by mid oceanic ridges and volcanic vents

answer; i believe the correct answer is (a) nigeria is the largest african crude (oil) supplier; /// so revenue from petroleum;