Hi all, I’m a newbie to adenium and could use some advice. Last year I took a gamble and ordered an adenium and two plumeria off of ebay; Sadly they ended up sitting in customs for over a month before they were finally cleared, so by the time I got them in hand the grafted scion on the adenium had completely withered to the point of looking like a dried up piece of grape stem, and a couple of days later it fell off the plant entirely.

Fast forward to this year and I’m left with the below, after the graft fell out three branches started to grow from the standard pink root stock, but as you can see only one of the branches kept growing, the other two have stayed tiny. So if I want to prune this plant to get some better branch growth should I prune it at line 1, 2, or 3? Any advice is appreciated :)