Correct option is (B) 14.5
Increased order of given observations is 10, 12, 14, 15, 16, 20.
Total number of observations is n = 6.
\(\therefore\) Median \(=\frac{\frac n2th+(\frac n2+1)th\text{ observations}}2\)
\(=\frac{(3^{rd}+4^{th})\text{ observations}}2\) \((\because\) n = 6)
\(=\frac{14+15}2\)
= 14.5
Hence, median value of the given series is 14.5.