The functional groups that are responsible for the ion-exchange property of cation and anion exchange resins, respectively, are :

• Correct answer
  A

  $-{\mathrm{SO}}_3\mathrm{H}\text{ and }-{\mathrm{NH}}_2$
• B

  $-{\mathrm{SO}}_3\mathrm{H}\text{ and }-\mathrm{COOH}$
• C

  $-{\mathrm{NH}}_2\text{ and }-\mathrm{COOH}$
• D

  $-{\mathrm{NH}}_2\text{ and }-{\mathrm{SO}}_3\mathrm{H}$

Hence, the correct answer is option: 'A'.