Answer: D) Rational Numbers
Any rational number is in the form p/q, where p,q are integers and q is nonzero.
If we made q = 1, then p/q turns into an integer which is why the set of integers is inside the set of rational numbers.
For instance, if p = 7 and q = 1, then p/q = 7/1 = 7 is an integer and it is rational too.
