UPSEE Solved Model Paper 7

Given
For any three sets A1,A2,A3
B1 = A1, B2 = A2−A1 and B3 = A3−(A1∪A2)
Drawing venn diagram of the given sets
B1 = A1
B2 = A2−A1 = A2∩A1°
[Using the definition of difference of two sets]
B3 = A3−(A1UA2) = A3∩(A1UA2)°

From, the Venn diagram, It rs clear that
B1UB2UB3 = A1UA2UA3
Hence, option ’B’ is correct