In the routing table, for network 172.16.0.0/26, what does serial 0/0/0 refer to?

(I do not have routing table picture)

Answer choices attached:

Select one: a. The interface on the next-hop router to send packets destined for network 192.168.1.6. b. The exit interface on the R1 router out which to send packets destined for network 172.16.0.0/26. c. The interface on the R1 router to which network 172.16.0.0/26 is directly connected