What event took place during the period known as realism

B) 1906 - First radio broadcast

Explanation:

The period of American realism began in 1870 and ended in 1910-1914 approximately. Such movement depicted social realities and the lives of ordinary people as they were, without embellishing them. And by the end of this period, on the Christmas Eve of 1906, the Canadian-born American inventor, Reginald Fessenden, transmitted the first wireless radio broadcast ever, from Massachusetts to the general public.

b) race riots in several cities