He clains the best builder in the town a) be b) to being c) to be d) being​

We live in a communal apartment.Apartment 2-bedroom, one bathroom ours, another family friend. Kitchen, bath, toilet, corridor naturally shared.But here's balcony years 15 is divided into two parts: one of our other.Exit to the balcony there is only from our room. Out of their rooms, and generally do not have windows to the balcony. They climb through the window in the kitchen.I do not know how it happened, that was their half of the balcony (I was fine escho year was 4), only know that before there was even a father with a tape measure climbed neighbors are measured gallop them. Well, quite a while so please leave them out, a year so 4 is privatized room. They all otmazyvatsya such times bath, toilet, kitchen, hallway general, the balcony too.To the lawyers did not apply (and probably in vain)Attached "plan apartment," Made John Paint
All our balcony there should be? And what the law of causality can be operated so that it and its neighbors to prove?