The answer is C because the earth gets hotter as you go deeper into it therefore the continental crust which is the outside would be the coolest. The inner core is the hottest then the outer core then the mantle and then the crust would be the coolest.
I'm pretty sure that it is oil because that is what most of the countries over there use it, making it a trend.
Answer: 1: Likely have some basis in truth
2: very important
Explanation: