In the legacy SBOK Create Sprint Backlog process represented by this question, important inputs include the Effort Estimated Task List, Length of Sprint, Previous Sprint Velocity, Dependencies, and Team Calendar, together with the Scrum Core Team. Therefore, the four factors listed in option C are all legitimate inputs.

Length of Sprint defines the available time-box. Previous Sprint Velocity provides historical evidence of how much work the team has been able to complete and therefore supports realistic commitment. Dependencies influence the order in which work should be executed. The Team Calendar records member availability, including leave, holidays, and other events affecting capacity.

The remaining options introduce artifacts that do not constitute this specific combination of Sprint Backlog creation inputs, such as Proof of Concept or Done Criteria.

In newer SBOK editions, the terminology has evolved toward Update Sprint Backlog, because an initial Sprint Backlog is created when User Stories are committed and is subsequently enriched with task-level information. The underlying capacity concepts—Sprint length, dependencies, team availability, and historical performance—remain relevant.

Therefore, C is the verified legacy SMC answer.

Study Guide reference: Plan and Estimate - > Create/Update Sprint Backlog - > Inputs; Sprint Planning.