Why does English use so many Greek and Latin root words?".

Which sentence is punctuated correctly? a) the moon which often shines too brightly in my window is full tonight. b) my new textbook which costs over thirty dollars is the best one i've ever read. c) mr. smith, who is a well-respected lawyer, has just retired from active practice. d) the play by velma winterbaker, that was published last year, ended up winning the pulitzer prize. '