Explanation:

The transfer of energy from one trophic level to the next in an ecosystem is governed by the '10% Law' of energy transfer, proposed by Raymond Lindeman in 1942. This law states that only about $10\%$ of the energy from one trophic level is transferred to the next trophic level. The remaining $90\%$ of the energy is lost, primarily as heat during metabolic processes, or is used for life processes such as respiration, growth, and reproduction, or remains unconsumed. \nOption A, '$100\%$ of the energy received by consumer', is incorrect because such a high transfer efficiency is biologically impossible due to the laws of thermodynamics (specifically, the second law, which states that entropy increases in an isolated system, meaning energy transformations are never $100\%$ efficient). \nOption B, 'Only organic matter is transferred', is partially true in the sense that energy is stored in organic matter, but it does not specify the *amount* of energy transferred, which is the core of the question. Moreover, it's the energy *within* the organic matter that is transferred, not just the matter itself in isolation from its energy content. \nOption C, '$10\%$ of the energy received by consumer', is the correct answer. This aligns with the 10% law, a fundamental principle in ecology explaining the decrease in biomass and energy at successive trophic levels. \nOption D, '$50\%$ of the energy received by consumer', is incorrect. While $50\%$ is a significant amount, it is far too high for typical energy transfer efficiency between trophic levels. Such high efficiency would lead to much larger biomass at higher trophic levels than observed in nature.