Q11,p3,j15. The relation schema R1 and R2 form a lossless join decomposition of R if and only if.

1. R1 intersection R2 -->>(R1-R2)
2. R1->R2.
3. R1 intersection  R2 ->>(R2-R1).
4.R2->R1 intersection R2.

codes
A) 1 and 2 happens.   B)1 and 4 happens.    C) 1 and 3 happens     D) 2 and 3 happens.

Answer C.

Explanation.
for lossless decomposition .Atleast one of the following dependencies should be in F+.

R1 intersction R2->R1.                     Eq. 1.
or
R1 intersection R2->R2.                    Eq2.

when a decompostion satisfies  eq 1. given above then that will solve the  R1 intersection R2 -->>(R1-R2).
when a  decomposition satisfies eq2 given above then that will solve the  R1 intersection R2 -->>(R2-R1).