| 1. | radioactive wastes |
| 2. | genetically modified hazardous microbes |
| 3. | methyl isocyanate gas |
| 4. | chlorofluorocarbons |
| Assertion(A): | Discharge of sewage into rivers can cause mortality of fish and other aquatic creatures downstream from the point of sewage discharge. |
| Reason (R): | Micro-organisms involved in the biodegradation of organic matter in the receiving water body consume a lot of oxygen, and as a result, there is a sharp decline in dissolved oxygen downstream from the point of sewage discharge. |
| 1. | Both (A) and (R) are True and (R) correctly explains the (A). |
| 2. | (A) is True but (R) is False. |
| 3. | (A) is False but (R) is True. |
| 4. | Both (A) and (R) are True but (R) does not correctly explain the (A). |