Redox action takes place during the process of:

Explanation

Redox reactions are crucial in both respiration and photosynthesis. In respiration, glucose is oxidized to produce energy, and oxygen is reduced to form water. In photosynthesis, water is oxidized, and carbon dioxide is reduced to form glucose. Therefore, both processes fundamentally rely on redox reactions, making Option D the correct choice. Growth, while essential for living organisms, does not primarily involve redox reactions, making Option C incorrect.