During a Sprint, when is new work or further decomposition of work added to the Sprint Backlog?

Not tending to something?

Who owns the sprint backlog in your opinion, and who is, considering this, allowed to change the content?

And from the timely perspective, when should communication about a new situation be started in your opinion?

BR,

It can't be C, because the Product Owner is not in a position to add work to the Sprint Backlog. Only the Development Team can do that, because they wholly own that backlog. Once a PO identifies new work, he or she can add it to the Product Backlog and request that the Development Team estimate it. It can then be brought into a future Sprint Planning session.

B is a plausible answer. The Daily Scrum is an inspect/adapt opportunity and it can certainly lead to the team revising their Sprint Backlog. However, it is not the *only* opportunity for them to do so. The Development Team can and should update their Sprint Backlog on an ongoing basis.

Therefore the best answer is probably A, although for better clarity I think it should really say "As soon as possible after they are identified by the Development Team".

Thank you very much for your answers. This helped me much.

Greetings,
Mark

So, would as soon as possible after identification?

A: As soon as possible after they are identified.

Eventually stories should't be introduced during the sprint (Hard Rule in Scrum). But to answer your question, B. Only team can decide/approves  

@Shiva Kumar Gosul, the following is the 4th paragraph of the Scrum Guide section where the Sprint Backlog is described (emphasis added by me). 

As new work is required, the Development Team adds it to the Sprint Backlog. As work is performed or completed, the estimated remaining work is updated. When elements of the plan are deemed unnecessary, they are removed. Only the Development Team can change its Sprint Backlog during a Sprint. The Sprint Backlog is a highly visible, real-time picture of the work that the Development Team plans to accomplish during the Sprint, and it belongs solely to the Development Team. 

Can you point me to somewhere that supports your "Hard Rule in Scrum"? 

Correct answer is A: As soon as possible after they are identified.

First of all the responsible to make change on  the sprint Backlog is the develop team.

Second , develop team make a changes to the Backlog during the sprint  "Work planned for the first days of the Sprint by the Development Team is decomposed by the end of this meeting, often to units of one day or less. The Development Team self-organizes to undertake the work in the Sprint Backlog, both during Sprint Planning and as needed throughout the Sprint."

Conclusion :  A: As soon as possible after they are identified.