The correct answer is Both (A) and (R) are true and (R) is the correct explanation of (A). • Deforestation results in the increase of CO2 in the atmosphere as deforestation lead to loss of forest cover. • Plant act as carbon sinks as they absorb carbon dioxide as it is required by them in the process of photosynthesis. • Hence assertion is correct and the reason is the correct explanation of assertion. • CO2 is one of the major greenhouse gas. Important Notes: • Other carbon sinks are: • Oceans and Soil • One of the leading causes of deforestation is agriculture and cattle grazing. • Forest land is frequently cleared and transformed into agricultural land in order to keep up with the ever-increasing demand for food. • Forests are a source of oxygen, food, clean water, and medicine. • The large mass of trees in forest areas combats soil erosion by providing mechanical support to the soil.