The TS has the ball joint that faces down, it's the one with the separate ball joint.

BMW call the other arm a wishbone on their parts list. Folk tend to call either or both control arms, wishbones, or whatever else they feel like.

My 2c is not to change the TS without changing the ball joint. I did and it made only a slight improvement. I did the bj later in the week and also the 'wishbone' and then it felt totally different and solid again, and my wishbones showed no sign of play at all, I just did them as they were the original wishbones after 110k