Question

question
which functional group is not present in this molecule?
answer
amino
carboxyl
sulfhydryl
hydroxyl
i dont know yet

Explanation:

The molecule has an amino group ($-NH_2$), a carboxyl group ($-COOH$), and a hydroxyl group ($-OH$). A sulfhydryl group is $-SH$ and it is not present in the given molecule.

Answer:

C. Sulfhydryl