Van der Waals' interactions refer to the weak attractive forces between molecules that are caused by temporary fluctuations in electron distribution. These interactions can be further subdivided into two types: dipole-dipole interactions and dispersion forces. Covalent interactions, on the other hand, involve the sharing of electrons between atoms in a molecule.

The correct order of interactions is:

b) Van der Waals'
c) Van der Waals'
d) Dipole-dipole

Explanation:

Van der Waals' interactions are the weakest of the intermolecular forces and are responsible for many physical properties of substances, such as boiling points and melting points. They occur between all types of molecules, including nonpolar molecules and polar molecules.

1. Van der Waals' interactions:
- Dispersion forces: These are the weakest type of Van der Waals' interactions and occur between all molecules, regardless of their polarity. They result from temporary fluctuations in the electron distribution around atoms or molecules, leading to the formation of temporary dipoles. These temporary dipoles induce similar dipoles in neighboring molecules, resulting in attractive forces.
- Dipole-dipole interactions: These occur between polar molecules and involve the attraction between the positive end of one molecule and the negative end of another molecule. This interaction is stronger than dispersion forces.

2. Dipole-dipole interactions: This is the next strongest interaction after Van der Waals' interactions. It occurs between polar molecules and is caused by the attraction between the positive end of one molecule and the negative end of another molecule. This interaction is stronger than dispersion forces.

3. Covalent interactions: These are the strongest type of interaction and occur within a molecule. Covalent bonds involve the sharing of electrons between atoms, resulting in the formation of a molecule. This interaction is much stronger than Van der Waals' interactions and dipole-dipole interactions.

In conclusion, the correct order of interactions is b) Van der Waals', c) Van der Waals', and d) Dipole-dipole. Covalent interactions are not listed in the given options because they are the strongest type of interaction and are not considered intermolecular forces.