I don't understand these two questions about sterols, please explain the correct answer?

Question

All sterols have

a. the same number of double bonds.

b. the same position of double bonds.

c. four rings of carbon to which other atoms are attached.

d. the same functional groups.

e. the same number and position of double bonds.

____ 35. Sterols are

a. lipids.

b. sometimes hormones.

c. components of membranes.

d. troublesome on walls of arteries.

e. all of these

Answer 1

First question - c. There are hundreds of different steroids and some of them are sterols, that is, they have at least one  -OH or hydroxyl group.  

Second question - e.  All of the above.  

Answer 2

d and e