Question

which numbers on the illustration are referring to the parts of the carbon cycle that release carbon into the atmosphere?

Explanation:

Step1: Identify decomposition source

Dead organisms and waste products (4) decompose and release carbon.

Step2: Identify vehicle - related source

Vehicle exhaust (6) from fuel burning releases carbon.

Step3: Identify plant respiration source

Plant respiration (2) releases carbon into atmosphere.

Answer:

1. Dead - organisms and waste products release carbon through decomposition; 6. Vehicle exhaust releases carbon from fuel combustion; 2. Respiration of plants releases carbon. So the correct options are 2, 4, 6.