The diagrams below represent the atoms or molecules that make up four different substances.

To analyze the statements:

A. **Hydrogen gas and argon gas are both made up of individual atoms that are not bonded together.**
- This statement is **partially true**. Hydrogen gas (H₂) consists of molecules made up of two hydrogen atoms bonded together, while argon gas (Ar) consists of individual argon atoms. So, it's not correct to say they are both made up of individual atoms that are not bonded.

B. **Liquid water and carbon dioxide gas are both made up of individual atoms that are not bonded together.**
- This statement is **false**. Liquid water (H₂O) consists of molecules formed from bonded atoms (two hydrogen and one oxygen), and carbon dioxide gas (CO₂) also consists of bonded atoms (one carbon and two oxygen).

C. **Liquid water, hydrogen gas, and carbon dioxide gas are all made up of molecules.**
- This statement is **true**. Liquid water is made up of H₂O molecules, hydrogen gas is made up of H₂ molecules, and carbon dioxide gas is made up of CO₂ molecules.

D. **Hydrogen gas, argon gas, and carbon dioxide gas are all made up of molecules.**
- This statement is **false**. Hydrogen gas is made of molecules (H₂), carbon dioxide gas is made of molecules (CO₂), but argon gas consists of individual atoms, not molecules.

Thus, the correct answer is:
**C. Liquid water, hydrogen gas, and carbon dioxide gas are all made up of molecules.**