Which of the following correctly describes the structural characteristics of sterols?

• A. Sterols have a fused ring structure composed of three six-membered rings and one five-membered ring.
• B. Sterols have a single six-membered ring and three five-membered rings.
• C. Sterols are linear molecules with no ring structures.
• D. Sterols consist of two six-membered rings and two five-membered rings.

Answer: (A)