Which of the following activities/processes can lead to global warming?
(i) Burning of fuels
(ii) Using mass transport systems
(iii) Using CFCs in refrigerators
(iv) Growing dense vegetations
(v) Increasing use of air conditioners
(vi) Digestion in cattle
(vii) Using electricity carefully
A(i), (iii), (v) and (vi) only
B(i), (iii) and (v) only
C(i), (ii), (iii) and (iv) only
D(i), (ii), (iii), (iv) and (vi) only