Which yeast would you re-use

#1 is yeast that was collected with extra beer from the primary. Its been in the fridge in a growler for two weeks.

#2 the secondary yeast that seems to like the dry hopping as I noticed the airlock has been busy .

US-05 that has made three batches already.

Primary yeast. Very, very likely the bubbling out of your secondary is just CO2 coming out of solution due to the dry hops being added, not yeast activity.

If given the option, always harvest the primary over the secondary - the yeast will be healthier and has a proven track record of finishing and flocculating.