It is A because the radius is 10 which means that if x=0 then y must equal 10. (0,5) would be inside of the circle. If this doesn't make sense graph the circle and the points and you'll see what I mean.
The graph on the top right would represent a function. A function line on a graph includes one line going in one direction. It's not 2 lines, its not just dots either and it definitely isn't in a square because, as I said, it goes in ONE direction. Hope this helped!
Yes, they are independent. First of all, we know that P(A) = 1/4, P(B) = 2/5, and P(A and B) = 1/10. To know if two events are independent, the following questions must be true: P(A)*P(B) = P(A and B). So since (1/4)*(2/5) = 2/20 which equals 1/10, these events are independent
