I don't understand. pls help

Witch one is it soo it the the question b.a,b,c,d

This map shows the member states of the european union (eu). based on this map, what is the most likely reason the eu was formed? a) to increase trade between european nations b) to protect themselves from foreign enemies c) to begin the process of forming one large nation d) to isolate europe from the rest of the international community j

Residents of moldova are mainly a. russian b. ukrainian c. serbian d. romanian the answer is d. romanian