Why did Germany begin a blockade?

A wish to retaliate and to break Britain's command of the seas motivated Germany to launch its campaign of unrestricted submarine warfare in 1917. The result was to make the blockade even more complete, by provoking the United States to join the Allies

Explanation:

c) they were beaten and fired from their jobs.

(202 bc - 220 ad) dynasty started by lui bang; a great and long-lasting rule, it discarded the harsh policies of the qin dynasty and adopted confucian principles; han rulers chose officials who passed the civil service exams rather than birth; it was a time of prosperity