What should be correct option for 1. and why...?
Answer : B
A is Correct. A Weak entity set in ER model doesn't have any key/Candidate key which can distinguish between any two records uniquely.
C is correct. We can have multiple Candidate keys in a relation.
D is correct. A Relationship can have its own attributes.
B is False (a Typo in Option B..It should be Relationship instead of relation)... In ER model, A Relationship between different Entity sets can be 1-1, M-N, 1-N, N-1.
Only is B is the Right Answer
B:EVERY RELATION CAN NOT BE 1:1 RELATION ,IT CAN ALSO BE 1:M AND M:N OR M:1 RELATION ALSO