Which of the following adds/add carbon dioxide to the carbon cycle on the planet Earth?
1. Volcanic action
2. Respiration
3. Photosynthesis
4. Decay of organic matter
Select the correct answer using the code given below.

Correct Option: 1, 2 and 4 only

Volcanic action, cellular respiration, and the decay of organic matter release carbon dioxide into the atmosphere, contributing to the carbon cycle. Photosynthesis, on the other hand, removes carbon dioxide from the atmosphere to produce glucose and oxygen.