Question

an organ or body system is best described as a...
collection of cells, all performing different functions with a unified purpose.
collection of cells, all performing the same function with a clear purpose.
collection of organs, all performing the same function with a clear purpose.
collection of organs, all performing different functions with a unified purpose.

Explanation:

An organ system is a group of organs with different functions working towards a common goal.

Answer:

D. collection of organs, all performing different functions with a unified purpose.