Final answer:
The major source of cholesterol in the list provided is butter, with spinach, quinoa, and egg white being lower in cholesterol, especially egg white which contains virtually none.
Step-by-step explanation:
The major source of cholesterol among the options provided is butter. Cholesterol is a waxy, fat-like substance that the body needs for making vitamin D, hormones, and cell membranes. It is also found in certain foods. High cholesterol levels can be attributed to consuming foods high in cholesterol as well as having a family history of high cholesterol. Among the options given, spinach, quinoa, and egg white are lower in cholesterol, with egg white containing virtually none. Liver, fish, chicken, and vegetable oils like wheat germ oil, corn oil, and safflower oil, as well as green leafy vegetables, lettuce, and egg yolk, are significant sources of cholesterol as well.