Given data:
The given tables.
A relation is said to be a function when single value of x gives single value of y.
Option (A)
It is not a function because the value 1 in first set have two images in second set.
Option (B)
It is not a function because the value 5 in first set have two images in second set.
Option (C)
It is a function.
Option (D)
It is a function.
Option (E)
It is not a function because the value 1 in first set have two images in second set.
Thus, the correct options are (C) and (D).