How did the posting of the "twelve theses" by students reflect nazi policy?

It called for the removal of Jewish influences from German language and literature.  This was in line with Nazi propaganda to keep the German race pure. The fact that it promoted that message was a warning sign for the Jews that they are now in danger.

The correct answer is: by supporting only German professors.  

Explanation:

They did not want someone that was not German coming in to teach their students; they wanted to be the dominant race and conduct ethnic cleansing.

may i see the answer choices?

then your answer is a

hoped that