Answer:
There are four alternatives
X- Z- W
X-W
Y-Z-W
Y-W
Explanation:
if X is founded, we cannot found Y or V so:
1)X- Z- W
2)X-W
if Y is founded, we cannot found X or V so:
3)Y-Z-W
4)Y-W
Z cannot be founded without X or Y
His alternatives are included in X and Y
if V is founded we cannot found W XY and Z can't be elegible without X or Y
There is no combination with V
W will be pick with X or Y and we have those cover, so we don't have a new alternative.