Data Sufficiency

1) The range of these 5 numbers is 9
2) The median of these 5 numbers is 21

==> In the original condition, the variable is 1(x), and in order for it to match the number of equations, the equation also need one as well. One 1)equation and one 2)equation, the answer is D with high chance.
In the case of 1), x=21,22 is possible, so it is not unique, thus not suffi. In the case of 2), x=21,22 is possible, hence not suffi. In the case of 1)&2) you get x=21,22 and it's also possible, thus not unique, hence not suffi. So the answer is E.
Answer: E

- Forget conventional ways of solving math questions. In DS, Variable approach is the easiest and quickest way to find the answer without actually solving the problem. Remember equal number of variables and independent equations ensures a solution.