The correct option is A upright
Pyramid of biomass represents a relationship between biomass and the trophic level. In tree and grassland ecosystem, the shape of pyramid of biomass is always upright. In this, the biomass is maximum at producer level, followed by primary consumer level (herbivores), followed by secondary consumer level (carnivores). The base of the pyramid of number represents the producers in a grassland ecosystem while the apex is the carnivores being less in number and biomass.