The thud of a hammer on rock rang through a remote valley in the Apurímac region. A worker from a nearby village swings a mallet and chips off the edges from a massive stone. That rock will form one...

The thud of a hammer on rock rang through a remote valley in the Apurímac region. A worker from a nearby village swings a mallet and chips off the edges from a massive stone. That rock will form one wall of the irrigation channel. He and a half-dozen others have been hard at work for a month already, and have rebuilt a good portion of it.

What is the central idea of this paragraph?

(I) It compares current farming systems to ancient ones.

(II) It connects Peru's history to its current challenges with farming.

(III) It illustrates the benefits of terrace farming.

(IV) It describes the efforts to rebuild the ancient farming systems

Choose all that is applicable