Which phrase indicates that a speaker wants to move away from the central topic for a moment and talk about something not included in the presentation?

A、Iwouldliketogobacktothetopicofbenefits.;
B、Iwouldliketomoveaheadthetopicofbadeffectsnow.;
C、IfImaydigress,Iwouldliketoaskyouwhatyouthinkaboutournewofficebuilding.;
D、Let’snowlookatthisbarchart.