Which of the following components would you be least likely to find in the earth’s mantle?

Idon’t quite understand this problem

Imagine you are standing in the antarctic during the southern hemisphere summer. the sky is clear and blue. there are no clouds in the sky. your shadow is cast on the icy ground. what is the color of the shadow?

(**i would really appreciate if this was answered soon** ) which pair of quantities includes one quantity that increases as the other decreases during simple harmonic motion?