GMAT Critical Reasoning (CR) | Compared to us, people who lived a century ago had very few diversions

Compared to us, people who lived a century ago had very few diversions to amuse them. Therefore they likely read much more than we do today.

Which of the following statements, if true, most weakens the argument?

A. Many of the books published a century ago were of low literary quality.

B. On average, people who lived a century ago had considerably less leisure time than we do today.

C. The number of books sold today is larger than it was a century ago.

D. On the average, books today