Question

the mohorovicic discontinuity, or _____, is a distinct group of thick, heavy rocks marking the boundary
moho
great divide
lower extremity
m-diverge

Explanation:

The Mohorovicic discontinuity is commonly referred to as the Moho. It is the boundary between the Earth's crust and the mantle. The other options - Great Divide (a major watershed in Australia), Lower Extremity (a body part term), and M - Diverge (not a recognized geological term for this boundary) - are not correct.

Answer:

Moho