The answer would be (B) Mediterranean. The Mediterranean climate stays between 60 and 30 degrees year round, and rarely dips below freezing. We can rule out tundra because it says below freezing year round. We can also rule out the highlands because the further up in elevation you go, the colder it gets. And finally, we can rule out the humid continental because its seasons are polar opposites. The humid continental has hot summers and freezing cold winters.
(Hope this helps!)