A prioritization matrix is used when a team must evaluate several possible factors, alternatives, or criteria and decide which deserve the greatest attention. In the CSSBB set of management and planning tools, the prioritization matrix is specifically intended to help rank options when there are multiple items competing for focus. That makes it well suited to situations in which several variables may be influencing process output and the team needs a structured way to compare them. By using weighted criteria or pairwise logic, the team can determine which variables or actions should be investigated first. Option A is incorrect because if all variables are equally important, prioritization would not be the purpose. Option B suggests that only a few variables matter, but the matrix is most useful before that conclusion has been reached. Option C describes a force field analysis type of problem, where driving and restraining forces are examined rather than ranked alternatives in a matrix. Therefore, the correct answer is that a prioritization matrix should be used when multiple variables might have an impact on process output.