The Decomposition D is lossless then it should satisfy any of the below two:
- (R1 ∩ R2) → (R1-R2) or
- R1 ∩ R2) → (R2-R1)
consider the ex: R(ABCDEF) which is decomposed into R1(ABCD) and R2(CDEF) , then this Decomposition becomes lossless when any of the below 2 satisfies:
- CD → AB or
- CD → EF
Therefore, I can say option C is correct.