The correct answer is C. Rutherford.
Rutherford conducted the gold foil experiment in 1911, which showed that the atom is mostly empty space with a small, dense nucleus at its center. This nucleus contains protons and neutrons, which account for most of the atom’s mass.
Thompson proposed the plum pudding model of the atom in 1904, which suggested that the atom is a sphere of positive charge with electrons embedded in it. This model was later shown to be incorrect by Rutherford’s gold foil experiment.
Bohr proposed the Bohr model of the atom in 1913, which suggested that electrons orbit the nucleus in fixed orbits. This model was later shown to be incorrect by the discovery of quantum mechanics.
Einstein is best known for his theory of relativity, which revolutionized our understanding of space, time, and gravity. He did not make any significant contributions to the study of the atom.