Which list shows the correct order of living units, from smallest to largest?

The correct order of living units from smallest to largest  are: 1)  Molecule 2) Organelle  3) Cell  4) Tissue  5) Organism  6) Population.
A molecule is the smallest particle in a chemical element that has the chemical properties of that element or compound.
An organelle is a tiny cellular structure that performs specific functions within a cell. Meaning they are smaller than cells.
A cell contains the fundamental molecules of life and of which all living things are composed of.
Tissue is a group of cells found together in the body. 
Organisms are made up of organs, which are made up of tissues.  It is a living thing that can function on its own.
Population are groups of living things that live together in a particular area. They are capable of interbreeding.

Well if you pick a machine to work on and that's gonna be your exercise if you don't stick to that machine your muscle strength your muscle mass rather will change because you haven't been doing it you change something in your exercise routine which changes your body's form of dealing with things for example you might become weaker or stronger depending on what kind of exercises you do in whether or not the machine you picked actually your muscles grow.