Answer :
The answer is\ compound, B. A compound is a particle made of molecules from various components. All mixes are particles, however not all atoms are mixes. Hydrogen gas (H2) is an atom, however not a compound since it is made of just a single component.
The correct option is option D i.e. Compound.
A compound is made up of two of more elements which are bonded chemically. For example,Water is a compund. It is made of two elements oxygen and hydrogen. One oxygen atom and two hydrogen atoms combine to form water i.e. H2O.