Which sentence could be added to the passage to best support the idea that World War I was a "calamitous" event?

to answer this question you need to explain more

apartheid, (afrikaans: “apartness”) policy that governed relations between south africa's white minority and nonwhite majority and sanctioned racial segregation and political and economic discrimination against nonwhites. people should not get this wrong. i was just answering a question.

the answer is mass marketing.