OK A to 04 UCS C2 AND UCI Which of the above une cases can be used by X2 CUC UC4 UC AND UC3 CUCA UCS AND CR son optional) part of UCH BUCS UC AND US Which actor interact with the system using UC4 CX AND X3 Which of the above actors is an abstract actor? UC2 UCS AND UCS XX2 AND X3 landi UCHUC2 UCZUC4 ADUCS con interact with the system through SULUI -U01UCG AND UCI a computer-) portot UCH ue UC AND UCS on abtroct with steps of its own US C2 UCS AND UCU