Which statement about the design is true?

Refer to the exhibit.

An engineer is addressing an IS-IS design issue which is running within the topology. All links are running on FastEthernet, except the link between R5 and R4, which is Gigabit Ethernet.

Which statement about the design is true?
A . R4 prefer to reach R5 using R1 as the next hop
B . All links have equal cost if the default metric is used
C . R5 prefers to use R4 as the next hop for all routes
D . R1 prefer to use R5 as the next hop to reach R4

Answer: B