Final answer:
Real numbers and Complex numbers are closed under multiplication, but Rational numbers and Irrational numbers are not closed under division.
Step-by-step explanation:
Both the Real numbers (which include rational and irrational numbers) and the Complex numbers are closed under multiplication.
For example, when you multiply two real numbers or two complex numbers, the result will also be a real number or a complex number, respectively.
However, neither the Rational numbers nor Irrational numbers are closed under division.
For example, when you divide two rational numbers, the result may be an irrational number, and when you divide two irrational numbers, the result may be a rational number.