Hello I’ll like to get a quick response on my question I’ll give brainliest to the first one or the one that looks like makes more sense thank you!

B

Explanation:

If the crate is stationary that means that the sum of forces is 0

both 1200 N alredy cancel themselves because they are opposite

so we need to cancel the 800N

800 -x =0

x=800 N

sure im new too!

explanation:

answerca air mass;