Correct Answer - Option 3 : Both S1 and S2 are false.
Answer: Option 3
Concept:
Foreign Key :is the set of attributes in a particular relation whose values are belongs to primary key of same relation or other relation.
Explanation:
Statement 1: A relation scheme can have at most one foreign key.
There is no such restriction on how many number of Foreign keys a particular relation can have. A relation can have as many number of Foreign keys as Required.
So this statement is false.
Statement 2: foreign key in a relation scheme R cannot be used to refer to tuples of R.
There is no such constraint. Foreign key can be used to refer to primary key of the same relation. Self-referencing relations are examples of such foreign key. So this statement is also false.
So option 3 is the correct answer.