Which process is cyclical? but we may be increasing its rate through air pollution

The answer is the carbon cycle.

Through are air pollution , we are increasing the amount of carbon dioxide in the atmosphere. This is exacerbated by the fact that we human activities are destroying carbon sinks such as forests where carbon dioxide is sequestered.  Consequently, the carbon dioxide in the air, which acts as a greenhouse gas, causes an increase in global warming.

The process that is cyclical in the atmosphere is the production of carbon dioxide but we have increased the rate of carbon dioxide in the atmosphere alarmingly that it can no longer be considered as cyclical.

Explanation:

The carbon foot print of the atmosphere is generated through the organisms that exhale carbon dioxide majorly in the atmosphere and this carbon dioxide in turn is utilized by the plants for the process of photosynthesis, increasing air pollution has increased the levels of carbon dioxide.

the answer to your question is:

c. complementary base-pairing

the answer would be..

b. sucking