正解:C
Currently, track 14uses the Boolean andoperator, meaning all three IP SLA objects (11, 12,
13) must be up for the route via ISP1 to stay active. If any one of them fails, the condition fails and the router incorrectly switches to ISP2.
To ensure the router only switches to ISP2 when all three probes fail, the trackobject should use the oroperator. This way, as long as at least one probe is successful, the route via ISP1 remains valid.