As a result of the holocaust, poland’s population today is significantly than when compared to pre-world war ii numbers.
a. catholic / lower
c. gypsy / higher
b. jewish / higher
d. jewish / lower

As a result of the Holocaust, Poland lost a significant amount of people - around 6 million (out of around 30 million). This was mostly a Jewish population, so the Jewish population in Poland is significantly lower than before the war - the correct answer is d). (there is almost no Jewist population currently).