Sql query question


There are 2 relations: gate2016 (exam_date, exam_center, branch_id) and candidate (rollno, name, bid, refno, choice_of_date). In a candidate relation, bid is the foreign key which refers to the key of gate2016. Suppose an insertion into candidate relation and deletion from gate2016 relation is done, then which of the following statement is true?
(a) Insertion into candidate relation can cause inconsistency
(b) Deletion from gate2016 relation can cause inconsistency
© Both operations can cause inconsistency of data
(d) None of them can cause inconsistency of data