Can you explain a little more what you don’t understand? Do you know what the #menu selector is? Do you know how to set the background color property? If not, you can look at the body selector above because you previously set the background property on that element but then commented it out.
I’ve edited your code for readability. When you enter a code block into a forum post, please precede it with a separate line of three backticks and follow it with a separate line of three backticks to make it easier to read.
You can also use the “preformatted text” tool in the editor (</>) to add backticks around text.
This is how you set the background color property to burlywood for the body element. But then you added /* and */ around it to comment it out. If you don’t want to comment it out, then you remove the /* and */. So now that you know how to set the background color to burlywood for the body element, why can’t you do the same thing for the #menu element?