The given Bar Graph presents the number of students of two schools for six years.

In which year, the percentage increase in students in school B is the highest in comparison to its previous year?

There is a decrease in number of students in school B in 2010,2013 compared to its previous year respectively

Percentage increase in number of students in school B in 2009 compared to its previous year$$=\frac{\left(820-550\right)\ }{550}\times100=49.09$$

Percentage increase in number of students in school B in 2011 compared to its previous year$$=\frac{\left(750-600\right)\ }{600}\times100=25$$

Hence, the correct answer is Option C