Their outermost shell has the maximum number of electrons it can hold.
Elements only react with each other to gain electrons to complete their outermost shell. Since noble gases already have a complete outer shell, they're usually inactive.
Answer:
D is rhe answer of rhis question.
Explanation:
collection of cells make tissue, collection of tissues form organ, similarly group of organs combine to form a system and when these systems combine it forms a whole body of organism.
I think its D I'm not quite sure but with RNA the A changes to a U.