so it's either a or b.
but let's try to see things in a bigger picture and try to include the situation of Barca. (what we didn't do yet)
Lorbek is traded at June 23rd to the Spurs. on 24th Barca picks the TO they have for the 3rd year of his contract.
we know that Lorbek already had a NBA buyout clause in his contract.
what if Lorbek wanted to join the Spurs (and the whole scenario was already checked by Spurs and Pacers FO and Lobek's agent), even with the risk of a lock out. in that case it was just good business by Barca to pick the option to secure the buy out fee.
however, let's think about the other scenario, Lorbek wants to push Barca to terminate the 3rd year and give him a bigger contract (maybe even for a longer period). I'm not sure Barca is willing to do so. they still have enough size in Vasquez, Perovic and Ndong and they already spent a lot of money for extending Vasquez and Mickeal. they need to replace Morris and Anderson.
the loss against Pana in the Euroleague wasn't a lack of size, it was more about power and athleticism. IMO Barca will rather invest in that department, before they try to keep Lorbek at any costs.
whatever we read into this, IOM the chance to sign him might be better than thought in the first place.