下列物质中，属于氨基酸的是：            

A．NH₂—CH₂—COOH                  B．NH₂—CH₂—CH₂OH 

NH₂                                                        COOH

C．NH₂—CH—(CH₂)₂—COOH            D．HOOC—CH—CH₂—COOH

下列物质中，属于氨基酸的是：            

A．NH₂—CH₂—COOH                       B．NH₂—CH₂—CH₂OH 

NH₂                                                                COOH

C．NH₂—CH—(CH₂)₂—COOH                D．HOOC—CH—CH₂—COOH

下列物质中，属于氨基酸的是：            

A．NH₂—CH₂—COOH                       B．NH₂—CH₂—CH₂OH 

NH₂                                                              COOH

C．NH₂—CH—(CH₂)₂—COOH                D．HOOC—CH—CH₂—COOH

下列物质中，属于氨基酸的是：            

A．NH2—CH2—COOH	B．NH2—CH2—CH2OH NH2COOH
C．NH2—CH—(CH2)2—COOH	D．HOOC—CH—CH2—COOH