Which of the following traits is acquired?
a. the number of petals that grow in a plant's flower
b. the wing shape of a wild bird
c. the ability of some gorillas to use sign language
d. a cheetah's ability to run faster than any other land animal

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.

the answer would be 3

if you know your abc's you should be able to get your answer or just use google