Which choice describes the heart? A. An indusial cell
B. A group of one cell type working together
C. A series of organs working together
D. A structure made of tissues that work together

D

Explanation:

it is not c since the heart is one organ

and it is not b since there is more than just muscle in the heart so more than one kind of cell

and for a i assume you meant industrial cell which is a machine part  

d is the answer heart an organ has 2 or more kinds of tissue that preforms a particular function

what school and grade?

c should be the answer