Use the KWL chart to answer the question. A 3-column table with 1 row. Column 1 is labeled What I Know with entry Rovers are Used to learn about Mars. Taking pictures is one of a rover's jobs. Column 2 is labeled What I Want to Know with entry What are some things scientists have learned by studying pictures of Mars? Column 3 is labeled What I Learned with entry Blank.
Talia read this excerpt from "Exploring Mars.”

1) A human face seemed to peer out of the photo. 2) The face was huge—almost two miles long. 3) It rose from the ground. 4) Other large landforms appeared in the photo. 5) These mesas were natural features of Mars. 6) Scientists believed that the face was just one of the mesas.

Which sentence would be the best choice for Talia to add to the "What I Learned” column to sum up what she learned in the paragraph?

sentence 1
sentence 2
sentence 4
sentence 6