B. because Hitler believed that using genocide was the solution to exterminating Jewish people. Known as the "Holocaust". Hope this helps!
Garibaldi wanted to unite Italy to make it more powerful. Many countries were united by then (maybe except for Germany, but the unification of Germany was just 10 years after the unification of Italy) and united countries were mostly more powerful.
It would be "b. regulating interstate and foreign trade," that is technically a non-legislative power of Congress, since this has to do with the commerce clause of the Constitution.