Which of the following is/are locally delivered antimicrobial(s) agent(s) used to treat infected periodontal pockets?
1. Metronidazole.
2. Chlorhexidine.
3. Doxycycline.
4. Clindamycin.

(1) (2) (3)

(1) and (3)

(2) and (4)

(4) only.

All of the above.