Rome Became Italy's Capital Due to the

Rome became Italy's capital due to the

A) entrance of Sardinia into the country.
B) French-Piedmont alliance.
C) forfeiture of Lombardy to France by Austria.
D) fact that Garibaldi succeeded Cavour and demanded that the French should turn oversight of the papal lands to the state.
E) fact that the Franco-Prussian War forced Napoleon III to return to France and leave Piedmont unprotected.