The correct answer is A. Decomposers
Step-by-step explanation:
In ecology and related, decomposers include organisms such as bacteria or fungi that differ from other organisms because they feed on dead matter or wastes. Moreover, decomposers are always located at the end of food chains or trophic networks because their role contributes to the existence of producers such as plants, considering decomposers return essential nutrients, minerals, etc. to the soil and these are used by producers. According to this, decomposers break down essential nutrients and return them to the soil.