Steroids are
complex carbohydrates
lipids
a subclass of fats
a type of phospholipids

The right answer is lipids.

Steroids are an important category of lipids, present in the animal and plant kingdom (cholesterol, vitamins D, sex hormones: estrogen and progesterone, testosterone and androsterone ...).

The basic structure of steroids consists of a polycyclic alcohol consisting of three hexagonal rings and one pentagonal ring.

Used in medicine, the word "steroid" refers primarily to steroid hormones.

heat a spark and oxygen

answer: - b cells

explanation: -

so, the b cells mediate their action by identifying the antigens present on the surface of the pathogens and then producing antibodies in return to mediate its effect.