Option C
If A= {1,2,3} and B= {1,2,3,4,5,6,7,8} then A U B = { 1, 2, 3, 4, 5, 6, 7 , 8 }
Solution:
Given that,
A = {1, 2, 3}
B = {1, 2, 3, 4, 5, 6, 7, 8 }
To find: A U B
A U B means union of set A and B
The union of two sets A and B is the set of elements which are in A, in B, or in both A and B
Therefore,
Combine the elements of set A and set B to get union of A and B
A U B = { 1, 2, 3, 4, 5, 6, 7 , 8 }
Thus option C is correct