Suppose we have a genericized class, Pair that has the form:

class Pair $\{$ private T e$1$; private T e$2$; public Pair$($T x$,$ T y$)\{...\}\}$

Which one of the following is the best description of T$?$

Group of answer choices

There has to be an existing Java class named $$T$$ elsewhere in the program.

T is a new Java data type that does not follow the usual type$-$checking rules of Java.

T is a type that does not need to be specified when the class is instantiated.

T is a type that is $$passed into$$ the class declaration when the class is instantiated or used.