The two subjects compared in the passage <em>"E-books or printed books? That's the question"</em> are people who read electronic books and people who read printed books.
The passage reflects on the digital revolution that also impacted reading, showing an increase in e-book sales, which in 2010 was 164%.
These indices demonstrate the change in consumer behavior, who now have the choice of reading a physical book, or an e-book through their smartphones, e-reader or tablet.
Therefore, the correct alternative is the letter c.
Find out more information about digital revolution here:
brainly.com/question/10377689
