Which of the following is true about -9? (1 point)
It is both an integer and a whole number.
It is a whole number but not an integer.
It is an integer but not a whole number.
It is an integer but not a rational number.
It is both an integer and a whole number.
It is a whole number but not an integer.
It is an integer but not a whole number.
It is an integer but not a rational number.