C because the key word effect so answer c say's some thingthing about it "establish" meaning later on, also stock exchange would be something major because it allowed them to have new things they could never get in there own country.
I think that Hitler saw in Austria the chance to increase the number of loyal, German soldiers - Austrians speak German and are culturally similar so it was easy to include them into the German army and so quickly acquire a great number of loyal soldiers who spoke the language and shared the culture with the Germans.
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