Which of these statements is correct about photosynthesis and decomposition?

both release carbon dioxide into the atmosphere.
both absorb carbon dioxide from the atmosphere.
decomposition absorbs carbon dioxide from the atmosphere but photosynthesis releases carbon dioxide into the atmosphere.
photosynthesis absorbs carbon dioxide from the atmosphere but decomposition releases carbon dioxide into the atmosphere.

The last option. Plants absorb carbon dioxide from the atmosphere, water from the soil and other nutrients also from the soil - salts containing nitrogene, potassium, sulphur, etc. They use water and carbon dioxide to produce sugar through photosyntesis. Decomposition is the reaction that converts any organic compound back into inorganic compounds - water, carbon dioxide and salts containing nitrogene, potassium, sulphur, etc. So it's basically the opposite. So photosyntesis uses carbon dioxide as a reactive and take it from the atmosphere, whereas decomposition generates carbon dioxide as a product and releases it to the atmosphere.