Answer:
The correct answer is A. Country X has the higher natural increase rate.
Explanation:
Natural increase rate is the excess of fertility over mortality, that is, the difference between the number of births and deaths over a period of time; making the basis for population growth.
As Country X has a crude birth rate of 40 and a crude death rate of 15, its population's natural increase rate is 25. In turn, Country Y has a crude birth rate of 20 and a crude death rate of 9, so its population's natural increase rate is 11. So, as we can see, Country X has a higher natural increase rate.
I'm not sure but I do think that it is A: rising magma.