Intermediate System to Intermediate System (IS-IS), Is a Protocol Used

Intermediate system to intermediate system (IS-IS) , is a protocol used by network devices (routers) to determine the best way to forward datagrams through a packet-switched network, a process called routing. A client has approached you about deploying very fast IS-IS hello timers across an intercontinental high speed SONET link. What's your option?

A) Fast hello timers are a good choice for this link because the length of the link indicates there will be at least one SONET amplifier that disables PATH alarms on the circuit.
B) Fast hello timers are a good choice for this link because on long haul SONET links the reporting of LINE and PATH errors can take a long time.
C) Fast hello timers are not a good choice for this link because the link is physically long and the propagation delay may cause IS-IS to believe the link has failed when it has not.
D) Fast hello timers are not a good choice for this link because SONET links provide link-down notification much faster than IS-IS could detect a circuit failure by means of hello processing.