Methods or procedures that are used to study living things.
Explanation:
A dichotomous key is a tool that allows the user to determine the identity of items in the natural world, such as trees, wildflowers, mammals, reptiles, rocks, and fish. Keys consist of a series of choices that lead the user to the correct name of a given item. "Dichotomous" means "divided into two parts".
Answer:
b. Living things
Explanation:
Every living thing contains organic compounds.