(E) says, "Most new machines and technologies make our lives more synchronized and productive."
The problem with (E) is that we know that the clock helps people to synchronize their affairs, but we cannot generalize this to all technological tools. Thus, (E) is out.
(A) says, "New machines and technologies can enslave as well as liberate us."
(A) is great because it accurately summarizes what the argument is about. The clock opened up new options for human productivity (liberating us), but it also made people constantly beholden to the notion of time (enslaving us). Thus, (A) is the correct answer choice.
Does this make sense? Let us know if you have any questions!
