How did new naval technology impact world war i?

a. germany engaged in unrestricted submarine warfare to gain tactical advantages.
b. the allies used u-boats to attack and sink german ships without warning.
c. navies became less focused on manpower since most submarines could operate on their own.
d. war at sea became less deadly since submarines were used to observe the enemy, rather than attack.

A. Germany engaged in unrestricted submarine warfare to gain tactical advantages.

Explanation:

During the First world war, unrestricted submarine warfare was first used by Germany . The areas around British Isles was declares a war and Germany threatened to attack the merchants ships even if it belonged to neutral countries.

It attacked many merchant ships and sank British ship Lusitania on May 7, 1915.  It was passenger ship and had 128 Americans on board. After this US President Woodrow Wilson demanded the German government to stop the attacks on the unarmed merchant ships.

German government responded by imposing restriction on its submarines and the German navy suspended the U-boat warfare.

(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

b) the confederacy had to pay all union war expenses.