To isolate them from the general population, jews in hitler’s germany were required to:

a) serve in the armed forces.
b) take their vacations in winter.
c) wear yellow stars.
d) live in the countryside.

The correct answer is C. Wear yellow stars

Explanation

During Hitler's dictatorship Jews were persecuted, imprisioned, exiled and killed. As a way to isolate the Jew population during Hitler's Germany Jews were required to wear a "Jewish badge" which consisted on a yellow star of David with the word "Jude" (Jew in Germany) on it, this considering the star of David is a symbol of Judaism. In this way, in Nazi Germany, it was ordered in 1941 the use of this yellow star to all the Jewish population over the age of six, this was a way to point out the Jew population and part of the persecution and discrimination of Jews in Nazi Germany, as any Jew could be  easily recognized by others and thus persecuted and discriminated. Because of this as Hitler persecuted Jews, making them wear yellow stars supported their discrimination and the antisemitism.

i think the answer's are a) b) and c)