Which of These Following Statements About Atoms Is Valid

Which of these following statements about atoms is valid?

A) The atom is the smallest particle that exists.
B) There are thousands of kinds of atoms, accounting for the great variety of substances.
C) There are nearly 100 different kinds of atoms found in nature.
D) Atoms are small building blocks of nature, being so small they cannot be photographed.
The word molecule can be at least partly identified by the following statement:
E) The molecule is the smallest particle that exists.
F) The molecule is the smallest subdivision of matter that still retains the chemical properties of the substance from which it originates.
G) Combinations of molecules form atoms.
H) The chemical elements consist of 105 different molecules, a list that keeps growing.