An open college is usually open admissions. That means that so long as you have a HS diploma or GED, you will get in. They let in everyone who applies, basically.
A selective college gets so many applicants that they have to screen out those who don't meet certain standards, so for a selective college, you'd need to be in a certain GPA level and/or have an SAT or ACT score that falls into a certain range to get in. They admit only a certain percentage of those who apply.
The correct answer is chemistry
I would say D. I'm guessing tho
The natural resources may not be able to keep up with the growth and some of the new population will starve or the population will ruin the natural resources.