HOOC-(CH2)4-COOH X3

Câu 77: Chọn D.

X5: HO-CH

2

-CH

2

-OH

X4: HOOC-(CH

2

)

4

-COOH

X3: HOOC-C

6

H

4

-COOH

X2: NH

2

-(CH

2

)

6

-NH

2

X1: NaOOC-C

6

H

4

-COONa

X: C

6

H

4

(COONH

3

)

2

(CH

2

)

6