0 votes 0 votes Deepalitrapti asked Aug 21, 2018 Deepalitrapti 317 views answer comment Share Follow See all 4 Comments See all 4 4 Comments reply manisha11 commented Aug 22, 2018 reply Follow Share I think all of them are right. As we can see B can't be derived from any FDs, therefore, it will surely be a prime attribute. Now we can take B closure; since B alone can't derive anything therefore we will make pairs as: [BA]+ = BACD (as BA->C and C->D) since we got all attributes here, therefore, AB is Candidate key. [BD]+ = BDAC (as D->A and AB->C) since we got all attributes here, therefore, BD is Candidate key. [BC]+ = BCDA (as C->D and D->A) since we got all attributes here therefore, BC is Candidate key. 1 votes 1 votes Deepalitrapti commented Aug 22, 2018 reply Follow Share But answer is c 0 votes 0 votes Deepalitrapti commented Aug 22, 2018 reply Follow Share @arvin 0 votes 0 votes arvin commented Aug 22, 2018 reply Follow Share @manisha yes well explained :) @deepali yes all are correct. it should be A,B,C,D. 0 votes 0 votes Please log in or register to add a comment.