You are managing a project schedule in Microsoft Office Project Standard 2007. The project activities occur in two locations. Project team members must travel between the locations by air and incur lodging expenses. The travel occurs on an irregular schedule, and expenses have varying costs, frequencies, and durations. You need to model the costs in the schedule as accurately as possible.
Which cost type should you use?

A.
budget resources

B.
cost resources

C.
per-use costs

D.
rate-based costs