Question

what are earths three main layers?
a core, mantle, and surface
b core, mantle, and crust
c inner core, outer core, and mantle
d upper mantle, lower mantle, and crust

Explanation:

The Earth's three main layers are the core (innermost), mantle (middle), and crust (outermost). Option A's "surface" is too vague. Option C lists inner and outer core (both part of the core layer) instead of the three main layers. Option D splits the mantle into upper and lower (sub - divisions of the mantle layer) rather than the three main layers.

Answer:

B. Core, mantle, and crust