I WILL GIVE BRAINLIEST Not one American soldier bound for Europe was lost to submarine attacks because of a.
alliances.
c.
convoys.
b.
airplanes.
d.
entente.

C. Convoys

Convoys are a group of ships or vehicles traveling together, typically accompanied by armed troops, warships, or other vehicles for protection, which allowed American soldiers to be less susceptible to attacks.

to replace ineffective because   andrew jackson's spoil system was a deliberate policy after he became president to remove federal employees he considered to be political opponents and replace them with his own supporters.