For complete protection ofa 3— phase line:
(1) Three phase and three—earth fault relays are required
(2) Three phase and two—earth fault relays are required
(3) Two phase and two—earth fault relays are required
(4) Two phase and one-earth fault relays are required
(1) Three phase and three—earth fault relays are required
(2) Three phase and two—earth fault relays are required
(3) Two phase and two—earth fault relays are required
(4) Two phase and one-earth fault relays are required