What process refers to the conversion of stored food reserves into useful energy in plants?

The correct choice highlights the important biological process known as respiration. This process enables plants to convert stored food reserves, primarily in the form of carbohydrates, into energy that is essential for growth, development, and overall function. During respiration, glucose and oxygen are utilized to produce energy, water, and carbon dioxide. This energy is vital for various cellular processes, including nutrient uptake, growth, and reproduction.

In contrast, photosynthesis is the process through which plants convert light energy into chemical energy stored in glucose, while fermentation typically occurs in anaerobic conditions and leads to energy production without oxygen. Transpiration involves the movement of water within a plant and its evaporation from aerial parts, playing a crucial role in nutrient transport and temperature regulation but not directly relating to energy conversion from stored food. Understanding these distinctions is key in recognizing how plants manage energy use and storage.