needn't have hurried
didn't need to hurry
needed not to hurry
had not needed to hurry
本题考查情态动词和虚拟语气。句意:当我们到达车站的时候,火车还没有到达,因此我们本不必这么匆忙。根据句意,后半句应用虚拟语气。needn't have done意为“本不必”。