Whatisthedifferencebetween1＋1and1:1protectionswitching?()

A.1+1isbasedonAPS，while1：1isbasedonIPS.

B.1：1isusedinSNCPswitching，while1+1isusedinMS-SPRingswitching.

C.1+1sendssignalsonWorkingandProtectpaths，while1：1sendssignalsonlyonWorkingpath.

D.1+1sendssignalsonWorkingpathONLY，while1：1sendssignalsonbothWorkingandProtectpaths.