Which of the following statements is/are True?
- If $x$ and $y$ are two integers whose product is odd, then both must be odd.
- If $a$ and $b$ are real numbers such that the product ab is an irrational number, then either $a$ or $b$ must be an irrational number.
- For any integer $m,$ if $m^{2}$ is even, then $m$ is even.
- The sum of a rational number and an irrational number is irrational.