How can a normally unreasonable cost become an allowable expense in a grant?

The correct answer reflects the principle that for an expense to be allowable under a grant, it must align with the goals and objectives of the grant. This means that even if a cost seems unreasonable at first glance, if it directly contributes to fulfilling the grant's purpose and objectives, it can be deemed acceptable.

Justifying costs in the context of a grant is crucial because funding agencies often have specific aims they want to achieve with their funding. If the cost is integral to achieving these aims, it becomes a necessary and allowable expense. For example, if a researcher is conducting a project aimed at developing new medical technology and requires specialized equipment that is costly but critical to the research, such a cost may be seen as allowable when it supports the project's goals.

The other choices, while containing relevant concepts, do not directly address the nature of the cost's relationship with the grant's goals. Sharing expenses with other projects or a federal requirement could make costs more justifiable in some contexts but do not inherently make normally unreasonable costs allowable. Documentation and approval by the sponsor are important aspects of grant management, but without alignment with the grant's objectives, the cost would not necessarily be justifiable.