Efficient pest control (has) reduced crop loss.
C. Stereotyping
Since they are saying "teenagers" they are building a stereotypical reference to teenagers and how they never listen...Hope this makes sense!
In this excerpt from Kennedy's 1963 Civil Rights Address, the idea that is being most clearly defined is B) equality.
He states that every American man or woman of any color should be equal, and that there shouldn't be any differences between white and black people.