The answer is B) relief
Relief is the is the difference in elevation between the highest and lowest points in an area.
The cyanide is

A carbon atom has 4 valance electrons and nitrogen has 5. Below is a Lewis-dot-structure of cyanide.
:N≡C.
The carbon atom is still one electron short of having a full octet and so it will seize another electron from almost anything, making the cyanide ion negative and whatever it took the electron from it now positive.
I believe the answer is B. a fruit falling from a tree
Chemistry is the branch of science that deals with the identification of the substances of which matter is composed.