input: [0] Phylum [1] Circulatory [2] Respiratory [3] Digestive [4] Reproductive [5] Excretory [6] Nervous [8] Muscular [7] 
output: Skeletal
options: S k e l e t a l
options: S p i c u l e s
options: N o n e
options: S o m e c o n t a i n s h e l l s
options: E x o s k e l e t o n m a d e o f c h i t i n