Another topic for fly to HKG for one day then fly back to SIN on next day. I have HK ID card.

I plan to fly on TG B77W to HKG from BKK and SQ B772 to SIN from HKG on next day in mid-Jan 2019.

A: TG600 BKK-HKG and SQ867 HKG-SIN

or

B: TG607 BKK-HKG and SQ867 HKG-SIN

Which one can I pick? A or B