Humans have contributed to habitat destruction by 1. clearing land for farming 2. excessive use of chemicals 3. producing green-house gases through use of fossil fuels 4. exploitation of land and water for mining of scarce resources Which of the above is/are correct?

• A.  1 and 2           
• B.  2 and 3
• C.  1, 2 and 3                    
• D.  All of these