Which of the following is / are valid code?

Question

a) System.out.println(Integer.add(2,2));
b) Float[] ar= new Float[] { new Float(1.0), new Float(2.1)};
c) System.out.println(Integer.toBinaryString(4));
d) System.out.println(Integer.cat(2,2));
e) System.out.println(Integer.toOctalString(4));

Answer 1

System.out.println(Integer.add(2,2));

Answer 2

a) System.out.println(Integer.add(2,2));