Question on about scrum team

Would you please give me your opinion on about below question:

A Scrum team is having difficulty developing a piece of functionality. As a self-organizing team, they: (Choose two answers)
A) Must figure it out themselves without outside help.
B) Ask the Product Owner to restore it to the Product Backlog.
C) May consult with people outside of the team.
D) Set it aside for the hardening Sprint.
E) Do whatever they can and identify the remainder of the work at the Sprint Review.


I think C and E is correct but as scrum says the Dev team should have all skill so not sure is that good candidate or not. (In real world the C is more realistic)

Thanks in advance,