42 The drug trafficking situation is one more potential strain on the already tense relationship between the UnitedStates and Canada.
(A) The United States and Canada have a tense relationship in recent years due to traffic problems.
(B) Drug smuggling adds a new strain on the tense US-Canada relations.
(C) The border transportation problem has long existed between the United States and Canada.
(D) The United States and Canada have a tense relationship along the border.