PT 40 S2 Q17

Each nonstop flight offered by Zephyr Airlines departs from one and arrives ... ...

If four of the cities are each connected with the remaining city, then the cities in which one of the following pairs must be connected with each other?
(A) Honolulu and Montreal
(B) ...
(C) ...
(D) ...
(E) ...

*This question is included in Spatial Games: Lesson Set 1 (of 1) - Intro