Which question can be answered by science? A. Which type of candy tastes the best?
B. Which kind of backpack do students purchase most often?
C. Why are children happy when they get home from school?
D. Why should we help those less fortunate than us?​

B. Which kind of backpack do students purchase most often?

Explanation:

This is something that scientists can count as well as graph to show statistics and solid numbers.

i think it would be b. tissue because 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.