Refer to the exhibit. How was the host route 1/128 installed in the routing table?

R1# show ipv6 route


s ::/0 [1/0]
via Serial0/0/0, directy connected
C 2001:DB8:CAFE:1::/64 [0/0]
via GigabitEthernet0/1, directy connected
L 2001:DB8:CAFE:1::1/128 [0/0]
via GigabitEthernet0/1, receive
C 2001:DB8:CAFE:2::/64 [0/0]
via GigabitEthernet0/0, directy connected
L 2001:DB8:CAFE:2::1/128 [0/0]
via GigabitEthernet0/0, receive
C 2001:DB8:CAFE:3::/64 [0/0]
via Serial0/0/0, directy connected
L 2001:DB8:CAFE:3::1/128 [0/0]
via Serial0/0/0, receive
S 2001:DB8:CAFE:4::1/128 [1/0]
via Serial0/0/0, directy connected
L FF00::/8 [0/0]
via Null0, receive

A. The route was dynamically created by router R1.
B. The route was dynamically learned from another router.
C. The route was manually entered by an administrator.
D. The route was automatically installed when an IP address was configured on an active interface.