The LSP “toR6” is configured with a fully strict path on a Nokia 7750 SR. Which of the following
configurations is required to enable fast reroute for this LSP?

Enable fast-reroute on all routers along the path, R1, R2, R4, and R6. 

Enable both link-protection and node-protection on router R1. 

Enable fast-reroute with either one-to-one or facility mode on this LSP. 

Enable link-protection only on router R4.