Which of the following is a type of steroid?

Cholesterol is a well-known type of steroid, which is a class of organic compounds characterized by a molecular structure consisting of four fused carbon rings. Steroids play important roles in various biological functions, including serving as hormones and components of cellular membranes. Cholesterol, specifically, acts as a precursor to several steroid hormones and is essential for the proper functioning of cell membranes.

Other options such as glucose, amino acids, and fatty acids do not fall under the steroid category. Glucose is a simple sugar and an important energy source for cells. Amino acids are the building blocks of proteins, while fatty acids are components of lipids, particularly triglycerides and phospholipids. Each of these compounds has distinct structures and functions that separate them from steroids. Therefore, cholesterol stands out as the correct choice in this context.