Answer the following question given this paragraph: 

There are many blood vessels in the kidneys ( Figure above ). The kidneys remove urea and other wastes from the blood through tiny filtering units called nephrons. Nephrons ( Figure below ) are tiny, tube-shaped structures found inside each kidney. Each kidney has up to a million nephrons. Each nephron collects a small amount of fluid and waste from a small group of capillaries.


Q: What are the tiny, tube-shaped structures found inside a kidney called?

 Choices:

- neurons

- jejunum

- dendrites

- nephrons

A:
nephrons
