what is the type of the object it references?

Given:
public class X implements Z {
public String toString() { return “I am X”; }
public static void main(String[] args) {
Y myY = new Y();
X myX = myY;
Z myZ = myX;
System.out.println(myZ);
}
}
class Y extends X {
public String toString() { return “I am Y”; }
}
interface Z {}
What is the reference type of myZ and what is the type of the object it references?

A.
Reference type is Z; object type is Z.

B.
Reference type is Y; object type is Y.

C.
Reference type is Z; object type is Y.

D.
Reference type is X; object type is Z.

Explanation:
Note: Because Java handles objects and arrays by reference, classes and array
types are known as reference types.