Answer:
A & C
Explanation:
You're looking for rational numbers that are also integers, but because (as the figure shows) ALL integers are already rational, you only have to worry about the integer part. An integer is a whole number, positive or negative. So, you need to simplify each element of each set (the numbers inside the curly braces) to see if they're whole.
A - The square root of 100 is just 10 or -10, divided by -2 is -5 or 5. 4, -2, 5, and -5 are all integers.
B - Wrong because 4/3 is not a whole number
C - 16/4 is just 4, and the square root of 49 is 7 or -7. 4, -6, 2, 7, & -7 are all integers.
D - Wrong because 27/2 is not a whole number
E - Wrong because 0.2 is not a whole number
Let me know if you need a more thorough explanation! (: