a); and c). During Chandragupta II reign, great impulse was given to arts and science. One of the main scholars of the time was Aryabhata, who came up with the concept of zero and discovered the ratio of pi. He also worked in demonstrating that the earth moves around the sun instead of otherwise.
Nazis built extermination camps equipped with huge gas chambers that could kill as many as 6000 human beings in a day. Those labeled as weak would die. They were told to undress for a shower and then led into a chamber with fake shower heads. After the doors were closed, cyanide gas poured from the shower heads. All inside were killed in a matter of minutes.
also if you use quizlet website it also has history stuff on there to.