A Sprint may be cancelled only if the Sprint Goal becomes obsolete. This makes Option A the correct answer. The Scrum Guide is very clear that only the Product Owner has the authority to cancel a Sprint, although that decision may be influenced by stakeholders, the Developers, or the Scrum Master. The reason for cancellation is not general disruption, poor forecasting, or the appearance of new work. It is specifically tied to the Sprint Goal no longer having value or relevance.

Option B is incorrect because a new business opportunity does not automatically justify cancelling a Sprint. Scrum is designed to handle change without disrupting the Sprint unless the Sprint Goal itself is no longer valid. Option C is incorrect because feasibility concerns should be addressed through collaboration and adaptation, but they do not by themselves define the cancellation rule. Option D is incorrect because not finishing all selected work is not a reason to cancel a Sprint. Scrum accepts uncertainty, and the team inspects and adapts. The Sprint Goal remains the key commitment, and as long as it is still relevant, the Sprint should continue.