During the war of Italian unification,why did French Emperor Napoleon III sign an armistice with Austria?

A) He did not want other countries to enter the war on Austria's side and was worried that a united Italy might become too strong and challenge French power.
B) He had lost too many men in battles.
C) French public opinion turned against the war.
D) He disagreed with his ally,the king of Piedmont-Sardinia,over tactics.
E) He lost his nerve due to the slaughter on the battlefield.

French Emperor

A title historically associated with Napoleon Bonaparte, who ruled France first as First Consul from 1799 to 1804, and then as Emperor from 1804 to 1814 and again in 1815.

Napoleon III

Nephew of Napoleon Bonaparte who became the Emperor of France (1852-1870), known for his expansionist policies and the modernization of the French economy.

Armistice

An agreement made by opposing sides in a conflict to stop fighting for a certain period, a truce often preceding a formal peace treaty.