Answer: The correct answer is 10% of the primary consumer's energy.
According to the law of 10 % energy transfer-
10 % of the energy is transferred from one trophic level to the subsequent trophic level in a food chain. The remaining energy is utilized in the metabolic processes of the organism or released as heat in the atmosphere.
Primary consumer ( like herbivore) and secondary consumer ( like carnivore) are the trophic levels of the food chain. Primary consumers get energy by consuming producers like plants whereas secondary consumers obtain energy by eating primary consumers.
Thus, 10 % of the energy from the primary consumer is transferred to the secondary consumer.