Review the KWL chart.

A 3-column table with 1 row. Column 1 is labeled What I Know with entry Mars is a planet. Column 2 is labeled What I Want to Know with entry Why did the Curiosity rover go to Mars? Column 3 is labeled What I Learned with entry Blank.
Read the excerpt from "Exploring Mars.”

While studying Mars, a rover named Curiosity had taken this strange photo. The rover had landed on Mars in August 2012. But it wasn't looking for rats. Its goal was to learn about the surface of Mars. The rover sent back many photos. One of them seemed to show a rat. Scientists said the "rat" was just a rock with a strange shape.

Based on the excerpt, what is the best choice to enter in the "What I Learned” column of the KWL chart?

The Curiosity rover didn’t get to Mars until August 2012.
The Mars rat picture was taken by the Curiosity rover.
The Curiosity rover was sent to study and take pictures of Mars.
The rat picture taken by the Curiosity rover was really just a rock.