Given the code fragment:
You have been asked to define the ProductCode class. The definition of the ProductCode class must allow c1 instantiation to succeed and cause a compilation error on c2 instantiation.
Which definition of ProductCode meets the requirement?
A.
B.
C.
D.
The correct answer is B. Option B defines the ProductCode class with a generic type parameter S that extends T, which means S must be a subtype of T. In this context, T is Number and S is Integer for c1, which complies with the constraint. However, for c2, T is Number and S is String, and since String does not extend Number, this will result in a compilation error. Therefore, it satisfies both conditions: allowing c1 instantiation and causing a compilation error on c2 instantiation.
B,tested
b is correct
B is correct, tested.
B is correct: String not extend from Number -> make c2 compilation error
Answer B