Consider the following statements regarding air pollution:1. The pollutant caused by incomplete combustion of organic matter is carbon monoxide.2. Depletion of ozone in outer atmosphere may trigger skin cancer.3. Acid rains are caused by SO2 and NOx.4. The permissible standard for SO2 in air for residential areas in India is 80 µg/m3.Which of the above statements are correct?

• A. 1, 2, 3 and 4
• B. 1, 3 and 4 only
• C. 2 and 4 only
• D. 1, 2 and 3 only