100
Humans have an appendix, a thin tube connected to the large intestine that serves no purpose and is a threat to human health and life if it becomes infected and/or inflamed. It is believed that the appendix once had a function as part of the human digestive system. The human appendix, therefore, is_____.
a. a homologous structure c. a vital organ
b. a vestigial organ d. a mutation
What is b.a vestigial organ