Answer
D' = {2,4,6,8,10,...... .}
Work Step by Step
U = {1,2,3,4.....}
D = { 1,3,5,7,9......}
The set D' contains the elements that are not present in the set D.
The elements of set D i.e. 1,3,5,7,9....... must not be present in set D.
The elements of D' are 2,4,6,8,10,......
Therefore D' = {2,4,6,8,10,...... .}