Final answer:
In sphingolipids, the structure is based on sphingosine, and fatty acids are attached by an amide linkage, which corresponds to option C. Sphingosine; amide linkage.
Step-by-step explanation:
In sphingolipids, the structure is based on sphingosine, and fatty acids are attached by an amide linkage. Therefore, the correct answer to the question is C. Sphingosine; amide linkage. Sphingolipids form a significant part of cellular membranes, with sphingomyelins and glycolipids being specific types that are derived from a ceramide core. Sphingomyelins, for example, contain a sphingosine unit, a fatty acid unit, a phosphoric acid unit, and a choline unit, creating a subclass of sphingolipids known as sphingophospholipids. These lipids are especially abundant in the brain and nerves, highlighting their importance in the function and structure of nerve cells and the myelin sheath.