Answer:
A. burning of fossil fuels
B. respiration
Explanation:
Fossil fuels such as petrol, diesel and coal are used in the movement of cars. These fuels are burnt inside the engine of vehicles and carbondioxide is released. Respiration is energy releasing process in which energy is released in the form of Adenine tri phosphate. In respiration, carbondioxide is released when glucose is broken down inside the mitochondria of the cell with the addition of oxygen.