Final answer:
Lipid-soluble substances are termed hydrophobic, while water-soluble substances are called hydrophilic; the correct answer is b. lipophilic | hydrophilic.
Step-by-step explanation:
Substances that are lipid-soluble are termed hydrophobic, meaning "water fearing", and do not mix well with water. On the other hand, water-soluble substances are called hydrophilic, which means "water loving" and interact easily with water, dissolving in it or being wetted by it. Therefore, the correct answer to your question is: b. lipophilic | hydrophilic.
Lipids in cell membranes are an example of amphipathic molecules with both hydrophilic (ionic and polar) and hydrophobic (alkyl groups and non-polar) parts. The hydrophilic parts interact with water, while the hydrophobic parts tend to separate from water and dissolve in nonpolar substances such as fats and oils.