What is a constraint in project management?

Correct answer: A limitation or restriction that affects how the project can be executed

Option C is correct because a constraint in project management is any limitation or restriction that bounds how the project can be planned and executed, such as a fixed deadline, capped budget, or required technology. Option A is incorrect because a risk is an uncertain event or condition that may positively or negatively affect project objectives, which is distinct from a known limitation. Option B is incorrect because a change request is a formal proposal to modify a document, deliverable, or baseline, not a restriction on execution. Option D is incorrect because an assumption is a factor held to be true for planning purposes without proof, whereas a constraint is a definitive boundary, not a supposition.