BMI-for-age charts are recommended to assess weight in relation to stature for children ages 2 to 20 years.The attached body mass index (bmi) growth chart with the outer limits of the curves at the 5^thand 95^thpercentiles are widely used by pediatricians as part of the routine clinical asessments. What is the bmi value at the 50^thpercentile for a 12-year old girl?

a.Approximately 22 kg/m2

b.Approximately 18 kg/m2

c.Approximately 26 kg/m2

d.Approximately 15 kg/m2