The real numbres are the numbers which include both rational and irrational numbers.
So in the figure,
We can see that, the group of rational numbers from real nubers have been selscted. So for the further grouping, we have take into consideration, the rational numbers only.
Rational number is a number that is expressed as the ratio of two integers, where the denominator should not be equal to zero.
Therefore, the next group would be integers.
Thus, the correct answer is option C.