The correct answer is A, because the Scrum Guide states that "a Sprint can be cancelled before the Sprint time-box is over. Only the Product Owner has the authority to cancel the Sprint, although he or she may do so under influence from the stakeholders, the Development Team, or the Scrum Master." Therefore, a Development Team cannot cancel a Sprint by itself.

The timebox for the Sprint Review is four hours for a one-month Sprint, as stated in [4]: "The Sprint Review is held at the end of the Sprint to inspect the Increment and adapt the Product Backlog if needed. During the event, the Scrum Team and stakeholders review what was accomplished in the Sprint and what has changed in their environment. Based on this information, attendees collaborate on what to do next. The Product Owner explains what Product Backlog items have been "Done" and what has not been "Done"; additionally, they discuss any changes to scope or budget or potential value. The entire group then collaborates on what to do next, so that the Sprint Review provides valuable input to subsequent Sprint Planning. The Sprint Review is a working session and attendees should inspect based on facts. A Sprint Review is held at the end of every Sprint for a maximum duration of four hours for a one-month Sprint."

According to the Scrum Guide, Scrum is a framework to generate value through adaptive solutions for complex problems. It is based on empiricism, self-organization, and collaboration. The other options are not accurate descriptions of Scrum, as they are either too rigid (such as a defined and predictive process or a complete methodology), too vague (such as a cookbook), or irrelevant (such as scientific management).

According to the Scrum Guide, the best approach for Scrum Teams in order to produce valuable Increments is to have each Developer work on the component where they feel that they can contribute. This means that the Developers can self-organize and collaborate effectively to deliver a valuable Increment that meets the Definition of Done and the Sprint Goal. The other options are not valid approaches, as they either imply that the Developers work in silos or rely on external people (such as developing functionality from beginning to end, working on an independent set of components, or working only as an independent layer of the system).

A Developer becomes accountable for an item in the Sprint Backlog never as Developers on the Scrum Team share accountability for items in the Sprint Backlog, as stated in the Scrum Guide: "The Developers can select whatever items they want as long as they feel they can complete the work by the end of the Sprint. The Scrum Team is responsible for all estimates. The Product Owner may influence the Developers by helping them understand and select trade-offs, but the people who will perform the work make the final estimate."