Here's a problem to solve: The modern theory of the atom is best described as the result of which of these activities?

Among the 4 following options, which is the correct answer?

- A: the experiments of John Dalton in the early 1800s
 
- B: the discussions between two important scientists
 
- C: the research of many scientists over many years
 
- D: the ideas of atoms by Democritus over 2000 years ago
 