The correct option is A A – partial regulators, B - regulators, C - conformers
Conformers their body temperature changes with the surrounding temperature they are also called ectotherms. 99% of animals are conforms.
Regulators some organisms are able to maintain a constant body temperature and constant osmotic concentration despite change in external environment. They are called regulators.
Partial regulators some organism have the ability to regulate their body functions to a limited extend called partial regulators. Beyond that limit they become conformers.
In the given graph, A represents the response of regulators. The internal levels of body are maintained constantly in spite of changing external levels.
The response B is of conformers. The internal body levels change accordingly with the external levels.
The responses C is of partial regulators. They are only capable of maintaining internal levels up to a certain limit.
So, the correct option is, 'A- Partial regulators, B- Regulators, C-Conformers '.