Which of the following methods are overloaded with respect to one another?

public int max (int a, int b) { ... }
public double max (double a, double b) { ... }
public int max (int a, int b, int c) { ... }
public double max (double a, double b, double c) { ... }

a. A and B are overloaded; C and D are overloaded.
b. A and C are overloaded; B and D are overloaded.
c. A, B and C are overloaded.
d. All four methods are overloaded.

d. All four methods are overloaded.