Final answer:
The union of the rational numbers set and the irrational numbers set is the set of all real numbers, as every real number is either rational or irrational. The correct answer to this question is C) the Reals.
Step-by-step explanation:
The question relates to the properties of different sets of numbers, specifically the rationals and irrationals. To find the union of set A (the Rationals) and set B (the Irrationals), we need to consider all elements that belong to either set A or set B, or both. Since rationals are numbers that can be expressed as a fraction of two integers, and irrationals are numbers that cannot be expressed as such a fraction, every real number is either rational or irrational.
The union of the set of all rational numbers and the set of all irrational numbers gives us the set of all real numbers. Therefore, the correct answer is C) the Reals.