The correct option is A 3
From the venn diagram we can write:
A={1,2,3,4,5,6}
B={1,2,5,}
Common elements between set A and Set B are: 1, 2, 5.
∴ the set corresponding to common elements between set A and set B = {1,2,5}.
∴ the number of elements in the set corresponding to common elements between set A and set B are 3.