First one is C. They believed the ships carried war materials to aid Great Britain. I do not want to steer you wrong with the second one, since I have no 100% sure answer. We have not got through to this part yet. This is if you are talking about WWI.
Germany attacked cargo ships primarily because they believed these ships carried war materials to support Great Britain. They also felt threatened by the presence of these ships. The Allies allowed Germany to move into Austria and Czechoslovakia without military response, making the appropriate answers C and D respectively.
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