Router R1 has been conf igured with an ipv6 route 2000::/64 S0/0/0 64 command.Which of the following does the 64 at the end of the command represent?（）

The following output occurs on Router R1 , which runs both EIGRP for IPv6 and OSPFv3, with redistribution from EIGRP into OSPF configured with the redistribute eigrp 1 metric 25 command. Interface S0/0/1 has been enabled for EIGRP ASN 1. Which of the following should be true of redistribution in  this case?（）
D 2000::/64 [90/1422516]
via FE80::213:19FF:FE7B:5026, Serial0/0/
1
C 2000:0:0:1::/64 [0/0]
via Serial0/0/1, directly connected
L 2000::1:213:19FF:FE7B:5004/128 [0/0]
via Serial0/0/1, receive

Router R1 currently has no configuration related to IPv6 or IPv4. The following configuration exists in a planning document, intended to be used to copy/paste into Router R1 to enable OSPFv3 on interfaces F0/0 and S0/0/0. No other related configuration exists. Assuming F0/0 and S0/0/0 reach an up/up state, which of the following is true about OSPFv3 on R1 after this configuration has been pasted into R1?（）
ipv6 router ospf 1
ipv6 unicast- routing
interface f0/0
ipv6 address 2000 ::1/64
ipv6 ospf 1 area 1
interface s0/0/0
ipv6 address 2001::/64 eui - 64
ipv6 ospf 1 area 0