Giuseppe Garibaldi helped the nationalist cause by

Garibaldi led the Redshirts in a campaign that conquered Sicily and much of southern Italy in 1860. He then handed these territories to Victor Emmanuel II, the king of Sardinia, helping unite them with the northern kingdom and advance Italian unification. This matches choice A; the war to free Lombardy was led by the king of Sardinia and his allies, not by Garibaldi.

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