Looks to me like the answer is B.
Are you sure about the 1st statement?
Is it 7<x>11?or is it 7<x<11?
If we go with 7<x>11 -
Statement(II)
(x+2+7+11+16)/5 = x
so x = 9
II is SUFF
Statement (I)
x=9 and x=19 will both satisfy the criteria.
we know that x=9 works.
Now if x=19 , the series becomes 2,7,11,16, and 19. The average of this series is equal to 11 and so is the median.
If this is the case, then Statement I is INSUFF
Hence, the answer is (B)
We cannot assume x as the median in this statement.
But if statement (I) is 7<x<11, then we know for sure that x=9. And if that's the case, (D) is the right answer.
But again, not sure if the inequality given in statement (I) is - 7<x>11 or 7<x<11. Could you please shed some light on this?
Thanks