Eukaryota Is The Correct Answer
So white blood cell’s(WBCs for short) main job is to fight infections.
They do this by swallowing the infection.
You see,WBCs do not have a permanent shape.this means that they enlarge and decrease size of parts of their body.So they grow two long arm like structures called pseudopodia which swallow the infection.(pseudopodia means false feet).
You can see the process in the photo I attached from google
It would b B.physically because solution is a mixture and mixture is formed by physical change not by chemical
They are thought to have separate paths of evolutionary development.
They developed along different evolutionary paths.
They had independent evolutionary development.