Question

The is the rigid outer layer of the Earth.
a. Core b. Mantle
c. Crust d. Inner Core

Answer 1

The rigid outer layer of the Earth is C. Crust.
The crust of the Earth is till the depth of 75 km deep into the Earth.
So, that means the mantle starts from a distance of 75 km after you go 75 km deep into the Earth from the sea level or the surface as you can say.

Answer 2

The rigid layer of Earth is (C) Crust.