Which of these layers is the Earth’s outermost layer? A.
the crust
B.
the mantle
C.
the inner core
D.
the outer core

A. Crust

Explanation: What is the outer layer of the Earth? The outer layer of the Earth is the crust, a hard thin layer that is composed of continental and oceanic crust.

Hope this helps^^

the answer would be the third option, "no, ariel should have added 9^2 and 12^2 and compared that to 15^2."

this is found through the pythagorean theorem, which is a^2 + b^2 = c^2.

this is the correct way of solving the problem:

9^2 + 12^2 = 15^2

81 + 144 = 225

225 = 225