U is the set of natural numbers less than or equal to 8B is the set of even factors of 8O (1, 2, 3, 4, 5, 6, 7, 8)O (1, 3, 5, 6, 7)O (2, 4, 6, 8)0

The natural numbers less than or equal to 8 are :
U = {1, 2, 3, 4, 5, 6, 7, 8}
The even factors of 8 are :
B = {2, 4, 8}
Note that the complement of B is the set of elements in U that is NOT in B.
This will be :
B' = {1, 3, 5, 6, 7}
The answer is B. {1, 3, 5, 6, 7}