We subtract the enthalpies of the reactants from that of the products:

Since this is < 0, this is an exothermic reaction.
The crust because there are tectonic plates.
Depends on what the problems are, you are going to have to be a bit more specific, Young Padawan
Answer:
A
Explanation:
CH4+O2-CO2+ H20
that mean methane has burn in oxygen to produce CO2