The RACI chart is a common type of Responsibility Assignment Matrix (RAM) used in project management to clarify roles and responsibilities. According to the PMBOK® Guide, it is essential for ensuring that there is no ambiguity regarding who is doing the work and who is making the decisions.

Why Choice B is correct: The acronym RACI stands for:

Responsible (R): The person who actually performs the work to complete the task. There is typically at least one " R " for every task.

Accountable (A): The " owner " of the work who must sign off or approve the deliverable. Crucially, only one person can be accountable for each task to ensure clear lines of authority.

Consult (C): People whose opinions are sought (two-way communication). These are usually subject matter experts (SMEs) who provide input.

Inform (I): People who are kept up-to-date on progress or completion (one-way communication).

Analysis of other options:

A, C, and D: These options are incorrect because they substitute the standard PMI definitions with words like " Recommend " or " Coordinate. " While these are actions that happen in a project, they are not the formal components of a RACI matrix. For example, " Recommend " is often part of the " Consult " phase, and " Coordinate " is a general management activity rather than a specific role assignment.

Key Concept: The RACI chart is particularly useful when a project involves cross-functional teams or multiple departments. It prevents " ownership gaps " (where no one is doing the work) and " duplication of effort " (where two people think they are accountable). By following the Choice B definitions, the Project Manager ensures that every task in the Work Breakdown Structure (WBS) is assigned to a specific individual or group with a clearly defined level of involvement.