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When a local loopback is activated on a PPP serial link……

When a local loopback is activated on a PPP serial link, what indicates that the local interface is good?()

A.A ping to the local address succeeds.
B.A ping to the remote address succeeds.
C.A ping to the remote address received a 'TTL expired' message.
D.The interface shows a flag indicating that a loop is detected.