Fact 1: Steroid hormones are made of lipids, such as phospholipids and cholesterol.

Fact 2: Steroid hormones are soluble in blood.

Given the two facts above, answer the question "what are soluble in blood?" with the following options: 
- viruses
 - lipids
 - glucose
 - Solutions
 - red blood cells
 - an ion
 - white blood cells
 - liquid


 

  lipids       