In which layer does mantle convection occur?

The correct answer is asthenosphere.

Explanation:

The Earth comprises four layers, that is, the crust, the mantle, the inner core, and the outer core. The magnetic field of the Earth is the amalgamation of the convection it attains from the Coriolis Effect and the outer core. The layer of the Earth where convection of the mantle takes place is the asthenosphere.