Hint: Ecological pyramid is an energy pyramid, where it is the graphical representation of the biomass in a given ecosystem, it mainly tells about how much energy is mainly retained by absorbing from sunlight and stored in the form food.
Pyramid of energy mainly tells about productivity, which means how much energy is transferred from one trophic level to another trophic level.
Biotic components of the pond ecosystem.
The biotic components of Pond ecosystem are various living organisms, which include
Producers in the pond ecosystem are divided into two types, they are phytoplankton: this are microscopic producers or autotrophs, examples are spirogyra, zygnema, etc and Macrophytes: this are large plants which manufactures large amount of food in the pond, examples are : hydrilla, pistea, etc.
> Primary consumers:
They are aquatic organisms, which mainly depend on the producers of aquatic life such as zooplankton, and Molluscs, beetles, cyclops.
Secondary consumers: This mainly depends on the herbivores for their food, examples are insects, fish, crabs, frogs, etc.
> Tertiary consumers:
They depend on both plants and animals for their food, they are omnivores, examples are large fishes and frogs.
Most of the decomposers are saprophytes, they may live in the sand layer beneath water, where most of the bacteria and fungi like asparagus are decomposers.
In the pond ecosystem, ecological pyramids are of three types, they are pyramids of biomass, pyramids of numbers and pyramids of energy, whereas energy pyramids are always upright in the pond ecosystem.
Hence, the correct answer is option (C).
Note: Other ecological pyramids such as pyramids of number and pyramids of biomass in the pond ecosystem are always inverted because, in the ponds the number and biomass of the consumers are more in number than the producers.