A Mayor is the leader of most citys
<span>During an unrestricted submarine warfare, one of the German U-boats had sunk the British passenger ship ,the Lusitania, at great loss of life. Public outcry in the U.S. led to America declaring war on Germany.</span>
Im pretty sure its true but not 100% correct .
The answer is A because the significance of gunboat diplomacy is military threats which is a foreign policy used to scare the less powerful nation so that they follow the most powerful nations demands.