Average = sum of terms/number of terms

k+m+r+s+t=16*5=80 and t =40

k+m+r+s=40

Now we need the maximum value the average could take or i.e. the value of r or to maximize r we need the minimum values for k and m in k < m < r < s < t

If k=1m=2 then r+s=40-3=37

So the median is 18 when s=19

Therefore the greatest possible value of the median of these 5 integers si 18

B is the answer