Concept:The fixed expression "no longer" shows that a past situation has ended.Explanation:The sentence means the friendship has stopped.We use "no longer" to say that something was true before but is not true now.The word "longer" fits correctly after "no" to form this expression.The other options do not form the standard phrase "no more," "no again," or "no always."So the completed sentence is: "We are no longer friends."Answer:B. longer