What are two reasons for the rapid population growth in the past 200 years

One reason that the population has grown in the past 100 years is because back in the day we did not have birth control. These days there are so many types of ways to kill your child in the womb. Now that there are more people living on this earth people have to find different places to live.  people are living in dangerous places just to survive.

It would be D because 3x2 is 6