Which one is an amino acids?
A. `CH_(3)-overset(NH_(2))overset(|)(CH)-overset(O)overset(||)(C)-OH`
B. `CH_(3)-CH_(2)-overset(O)overset(||)(C)- O-NH_(4)`
C. `CH_(3)-CH_(2)-overset(O)overset(||)(C)-NH_(2)`
D. `CH_(3)-CH-NH_(2)-overset(O)overset(||)(C)-Cl`
