What compound is this?
Carbohydrates
Lipids
Nucleic acids
Proteins

Answer:
Proteins.
Explanation:
Use these mnemonics:
Carbohydrates & Lipids - CHO
Proteins - CHON
Nucleic acids - CHONP
We can immediately eliminate carbohydrates and lipids, as we can see an "N". There is not a "P" visible either, meaning we can rule out nucleic acids. We are left with proteins.