By definition the interquartile range or IQR is obtained when the 25th percentile or
is subtracted from the 75th percentile or
.
Thus, from the above definition, the formula for IQR is:
![IQR=Q_(3)-Q_(1)](https://img.qammunity.org/2019/formulas/mathematics/high-school/suome19jw86o70hoo1o9q0pbsuh3rvdygh.png)
As we can see from the provided options that the definition of IQR matches the expression provided in Option A and thus, Option A is the correct answer.