Which statement is true about the product of a non-zero rational number and an irrational number?
A) The product of a non-zero rational number and an irrational number is always a rational number.
B) The product of a non-zero rational number and an irrational number is never an irrational number.
C) The product of a non-zero rational number and an irrational number is sometimes a rational number.
D) The product of a non-zero rational number and an irrational number is always an irrational number.