The correct option is A 0.03 J
The biotic (living) and abiotic (non-living) factors of a particular habitat interact amongst themselves to form a self-sustained and stable unit known as an ecosystem.
The biotic factors in an ecosystem are arranged at different trophic levels based on their source of food in a particular food chain. A food chain represents a linear relationship, of eating and being eaten, between organisms.
Given in the question is an example of a grazing food chain which starts with producers that trap the sun's energy to prepare food by photosynthesis. Here, grass is a producer. The grasshopper forms the next higher trophic level of primary consumers which feed on producers. The grasshopper is eaten by a secondary consumer such as a frog, which in turn is being eaten by a top carnivore such as a snake in this case.
As organisms of one trophic level feed on other organisms of a lower trophic level, energy flows through a food chain in the ecosystem.
In the given scenario, the energy trapped at the producer level = 30J
Only 10 % of energy is passed on from one trophic level to the next,
Hence, the energy available at the level of grasshopper (primary consumer) = (10/100) X 30 J = 3 J
The energy available at the level of frog (secondary consumer) = (10/100) X 3 J = 0.3 J
The energy available at the level of snake (tertiary consumer) = (10/100) X 0.3 J = 0.03 J
Therefore, the amount of energy available to a snake in the given food chain is 0.03 J.