In which three situations is incomplete recovery required？（） A: AAfter a shutdown abort. B: BWhen recovering to an SCN. C: CWhen recovering until a specific time. D: DWhen a required archived log is missing.

In which three situations is incomplete recovery required？（） A: After a shutdown abort. B: When recovering to an SC C: D: When recovering until a specific time. E: When a required archived log is missing.