The correct answer will be option A.
A scientific theory is a well-substantiated idea and opinion which explains the natural phenomenon. For a theory to be a scientific theory has to be:
1. well supported by the observations and experiments.
2. supported by repeated experiments and hypothesis.
Since in the question the scientific theory was proposed by more than one scientists who performed many experiments after Dalton who proposed the atomic theory. These scientists modified and revised the theory with their discoveries like JJ Thompson discovered electrons, Ernst Rutherford discovered protons and James Chadwick who discovered neutrons.
Thus, option A is the correct answer.