Which of these statements is true:
i. Cholate (a bile acid anion) and cholesterol have similar structures and fulfill the same functions in the body.
ii. Cholate's hydrophilic groups allow it to play an important role in membrane structure, similar to cholesterol.
iii. Cholesterol, with its hydroxyl group and hydrophobic tail, serves as an emulsifier, like cholate.
iv. Cholate has additional carboxyl and hydroxyl groups compared to cholesterol, making it effective as an emulsifier rather than a membrane component.