Estrogen belongs to which class of compound? carbohydrate
phospholipid
steroid
triglyceride
starch

Steroid.

Explanation:

Estrogens are a group of chemically similar steroid hormones. Steroids are a special kind of fat molecule with a four-ringed, carbon atom backbone, or core, like their cholesterol predecessor. A series of chemical reactions, spurred by proteins called enzymes, remove and add groups to cholesterol's core.