I think v is right. Judging from thе picture here - http://www.metropolitan.bg/bg/trans/ the station that is between Младост 1A and Младост 3 is called Младост 3. 14 is on the branch veering to the south.
I think they chose 3 instead of 1A to avoid potential confusion in the future between 1 and 1A.

About the naming - stations are named after three things - a nearby landmark (like the National Stadium, the University, etc.), the district they lead to or in which they are (Mladost, Lyulin, etc.) or when under or above a major intersecton -  after the street that is perpendicular to the metro's route (G.M. Dimitrov, Joliot Curie, the future Tsarigradsko Shose, etc.). Or, in the case of two future stations - after a square. But not after "what's on the next stop".