How did the hundred years' war effect medieval europe a) england became more interested in a continental empire b) the longbow and cannon made knights and castles less important c) france became more interested in trading overseas d) smaller armies led by feudal vallas became more important

B) the longbow and cannon made knights and castles less important.

Explanation:

The longbow and cannon are two of the developments that took place during the Hundred Years' War. These had a large impact on Medieval Europe. The longbow meant that knights were no longer necessary as single combat became less common. Moreover, cannons meant that castles were not immune to attack anymore. These conditions led to deep social and cultural changes.

the answer to your question is:

strong-mayor system