Vitamin a retinol function in the body​

Vitamin A has several important functions. These include: helping your body's natural defence against illness and infection (the immune system) work properly. helping vision in dim light.

Explanation:

if your own plato the answer is b. the fern transitioned from sporophyte generation to gametophyte generation.

organ system-an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.