Given the functional dependency R → (S,T) , then it is also true that R → S.

Answer: Option A

Option1: True
In the given functional dependency R ? (S,T), it means that the value of R uniquely determines the values of both S and T. Therefore, it is also true that R ? S, as the value of R uniquely determines the value of S. This is a valid implication based on the given functional dependency.

Option2: False
If R ? (S,T) is true, it does not necessarily mean that R ? S is also true. The functional dependency R ? (S,T) indicates that the value of R uniquely determines both S and T, but it does not specify that R uniquely determines S alone. Therefore, it is not always true that R ? S based on the given functional dependency.

In conclusion, Option1: True is the correct answer as the given functional dependency R ? (S,T) implies that R ? S is also true.