More than 90% of the Earth's crust is composed of silicate minerals, making silicon the second most abundant element in the Earth's crust (about 28% by mass) after oxygen. Ur Welcome.
Option A (Silicon) makes up 27.7% of the elements in the earth’s crust Option B (Magnesium) makes up 2.1% of the elements in the earth’s crust Option C (Nickel) is not found in earth’s crust. Option D (Iron) makes up 5.0% of the elements in the earth’s crust
The earth’s crust basically contains eight (8) elements namely: Oxygen, Silicon, Aluminum, Iron, Calcium, Sodium, Potassium and Magnesium (Listed in order of abundance). The only element that is more abundant that Silicon in the earth’s crust is Oxygen, which accounts for 46.6%.