A civilian is someone who is not in the military. Option B is correct.
A civilian is a person who is not involved in the armed services or the police force. Meanwhile a soldier is a person who serves in an army.
An officer is a person that holds a position of authority, particularly one with a commission, in the armed services, the mercantile marine, or on a passenger ship.
Finally, an immigrant is a person who moves out from he or she home country to a foreign one and stays permanently.
