In which year, the absolute difference between the numbers of students in two schools is the highest ?

The absolute difference between the number of students in two schools in 2010$$\ =\left|500-600\right|=100$$

The absolute difference between the number of students in two schools in 2011$$\ =\left|700-750\right|=50$$

The absolute difference between the number of students in two schools in 2012$$\ =\left|900-500\right|=400$$

The absolute difference between the number of students in two schools in 2013$$\ =\left|750-480\right|=270$$

$$\therefore\ $$The absolute difference between the number of students in two schools is highest in 2012.

Hence, the correct answer is Option A