The statement that is true of the Spanish flu is:
It was the worst pandemic of the twentieth century.
The Spanish flu pandemic of 1918-1919 is considered one of the deadliest pandemics in history, infecting about one-third of the world's population and causing an estimated 50 million deaths globally. The other statements are not accurate. For example, India experienced one of the highest death rates during the pandemic, and quarantines were often seen as detrimental to economies rather than beneficial.