A graphic representation of number of individuals of different species belonging to a particular trophic level in an ecosystem is known as:

The correct option is A. pyramid of number.

An ecological pyramid is a graphical representation designed to show either the number, biomass or energy at each trophic level in a given ecosystem. Each of the ecological pyramids have producers at the bottom level supporting consumers as we move towards the top of a pyramid. The ecological pyramids are of three types: pyramid of number, pyramid of biomass, pyramid of energy. The pyramid of number represents the total number of organisms at each trophic level.