"They arrived at a solution."
Translation:Ellas llegaron a una solución.
I was thinking that some group activity among themselves must have occurred for the solution to be agreed. Them arriving at a solution also reminded me of them meeting at some location or some point of time, which can be reflexive in Spanish, I think. Is there any way of predicting if a verb is reflexive? I have just noticed that if you approach a house Spanish uses acercarse, but if it is a problem, you need abordar