The correct option is B 8
Since, the ascending order of the given data is as:5,7,7,9,10,10.
And, the number of observations is 6, which is even.
So, the median of the given data
=12[(62)thobservation+(62+1)thobservation]
=12[3rdobservation+4thobservation]
=12[7+9]
=162=8
Hence, the correct alternative answer is (C).