Explanation:
1 and 17 are highly reactive bc they are almost full or not full at all. they need there last shell to be full in order to be happy, or not reactive. 18 has the noble gases which are not reactive at all bc they have a full valence shell and dont need any other electrons.
I guess it will be C: atoms and molecules because according to Jhon Dalton's
atomic theory :"all matter is made up of atoms"
and even if we think of other options think it by urself that not all matter is made up of them
When a bend in a river gets cut off...