Which choice is a valid implementation of this interface?
interface MyInterface { int foo(int x); }
public class MyClass implements MyInterface { // .... public int foo(){ return 100; } }
public class MyClass implements MyInterface { // .... public int foo(int x){ return x * 100; } }
public class MyClass implements MyInterface { // .... public void foo(int x){ System.out.println(x); } }
public class MyClass implements MyInterface { // .... public double foo(int x){ return x * 100; } }