No, "neither" implies two (not either). Choose B.

"Neither of" is used when the selection is only between two things where "none of" is used when there are a number of selections greater than two. With either/neither always think 2. That being said, the question is very poorly and ambiguously worded as "us" could easily mean any amount of people including 2. I am assuming the question wants you to answer B, however as a journey often takes many people. I would bring this up with your instructor, however, as such ambiguities get in the way of learning and understanding. Hope this helps :)

Hmm I'm not really sure why Randy says answer A is wrong. They both seem acceptable to me, just that choosing option A would mean that the "us" is referring to just 2 people, while it's referring to more than 2 people in option B. But maybe Randy's right and he's seeing something we're not seeing! @Randy, could you explain why you say option A is wrong?