AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.
(B) 10%
An average of 10% of the food eaten by an organism at one trophic level is turned into its own body mass and made available for the next trophic level.
The 10% law is a key concept in energy flow through ecosystems. The source passage explicitly states: "An average of 10% of the food eaten is turned into its own body and made available for the next level of consumers." The rest is lost as heat, used in digestion, or for work. This is why food chains are limited to 3–4 steps. Remember: green plants capture ~1% of sunlight energy, but 10% of food energy passes between trophic levels — don't confuse the two.
Source: Chapter 13, Section 13.1.1 Food Chains and Webs