问题：

[单选] Company network is implemting IPv6 into their existing IPv4 netwrok. Which statement is trueabout incorporating IPv6 into an already existing IPv4 network？（）

A . Only OSPF version 3 can be utilized for routing IPv4 and IPv6
B . IPv4 and IPv6 networks can be routed simultaneously
C . IPv6 can be routed using the same routing protocol versions as IPv4
D . A router routing for IPv6 and IPv4 must convert IPv4 packets to IPv6 packets to route them
E . None of the other alternatives apply