Which three are legal ways to declare and initialize an instance variable?

Which three are legal ways to declare and initialize an instance variable? (Choose three.)

A.
public Integer f = new Integer(42);

B.
static Integer f = new Integer(42);

C.
public Integer f = null;

D.
static int x = 42;

E.
public int x = ‘c’;

F.
public int x = null;