Plz help

Erika visits the Grand Canyon with her family. When she shouts near the edge, she can hear her voice echo throughout the canyon. Which statement describes why Erika hears her echo?

c.

Explanation:

Based on the information it can be said that the statement that best describes why Erika hears her echo is that the sound waves reflected off the canyon walls. An Echo is a sound that is repeated because the sound waves bounce off an object in the right way that it is reflected back towards its place of origin. Which in this case would be back at Erika after reflecting off the Grand Canyon's walls.

okay i have so many questions. but the big one here is: um wt..f is this mess? ?

where are the vectors ?