Match the following:
| Column A | Column B |
| P. Acridine orange | a. base analog |
| Q. 5-BU | b. intercalating agent |
| R. Ethyl methane sulfonate | c. deaminating agent |
| 5. HNO2 | d. alkylating agent |
1
P-b, Q-d, R-a, S-c
2
P-b, Q-a, R-d, S-c
3
P-b, Q-d, R-c, S-a
4
P-a, Q-b, R-c, S-d