I'd pick the biggest one.
I wouldn't but thats just me.
ok so I'm broke or cheap. Not really sure. But I just got a 5 pack of Buddha seeds auto syrup and I also got a dinafem critical + auto. The reason I only got a 5 pack is because I want to do a seed run and save money down the line...being the f up I am the autos work great for me. Someone told be I will have better results if I made f1 rather then s1 seeds. I understand that for whatever reason that f1 seeds will be more fertile. But which plant should I use as a host since genetically both will be female in turn producing fem seeds....
An f1 is a filial generation, meaning traditional breeding with a male and female, how will you guarantee all female?
S1's can result in fem seeds but you can also limit your gene pool, but limit is subjective....
I would pick with your gut or try and get a chemotype done....Biggest plants always seem to have problems like runts and don't guarantee the best smoke/medicine/resin whatever you are after...sometimes the runt bastards are the real diamonds...
Probably best to clone out your mothers and grow them out for a bioassay 1st. [Yes, I realize it is an auto and yes it can be done.] Have you even partook of this particular strain before? Just curious if you chose it from past reference?