The smallest unit of life is the best that describes a living cell.
Step-by-step explanation:
The cells are the smallest unit of living thing. A living thing is composed of one cell or more cells are known as organism. All living organisms are made up of cells they are the structural unit of organization.
The organisms that are made up of one cell is known as unicellular and the organisms that are made up of multiple cells are known as multicellular. Each and every organisms need energy to survive.
The group of similar cells combine and perform specific function is known as tissues.