Which two interfaces are considered to be functional interfaces?

@FunctionalInterface

interface InterfaceC {

public boolean equals(Object o);

int breed(int x);

int calculate(int x, int y);

}

@FunctionalInterface

interface InterfaceD {

int breed(int x);

}

@FunctionalInterface

interface InterfaceE {

public boolean equals(int i);

int breed(int x);

}

interface InterfaceA {

int GERM = 13;

public default int getGERM() { return GERM; }

}

interface InterfaceB {

int GERM = 13;

public default int getGERM() { return get(); }

private int get() { return GERM; }

public boolean equals(Object o);

int breed(int x);