Which of the following human activity affects the carbon cycle?

• The carbon cycle is the cyclic method of reusing the carbon atoms present in the environment. 
• The carbon atoms travel from the atmosphere to the organism and back into the atmosphere. 
• Human activities that include burning of harmful fossil fuels and also burning rainforest cause a major harm to the carbon cycle.
• Because of these activities the amount of carbon that is present in the atmosphere increases at a rapid rate. 
• This further leads to the rapid heating of the Earth’s atmosphere causing global warming.
• The carbon dioxide in the atmosphere is also absorbed in the oceanic water which decreases the pH of the water and causes severe harm to the plants and animals that live underwater.

Hence the correct answer is D.