The most specific would be felis catus. That is the name of the species in biology, and there are no more taxonomic divides after species.
Bones are made up of Calcium Phosphate given by the chemical formula, 
. When bones are kept in Hydrochloric acid, given by the chemical formula, HCl, they become soft because the calcium compound present in the bones changes its form. The following double displacement reaction takes place when the bones are kept in HCl,
---> 
Calcium chloride is water soluble, and gets washed away. This makes the bone thin and soft.
Cytoplasm is the gel-like fluid that fills the cell and surrounds the organelles.
I think the answer is c but I looked it up and got this: system or thing used as an example to follow or imitate.
