In this example, it says Rutherford's experiment with alpha particles scattering by gold foil established that A electrons are positively charged subatomic particles. Even if we didn't know anything about Rutherford's experiment, we should know that this statement is false. Electrons are not positively charged subatomic particles, they're negatively charged subatomic particles. Besides, it improve this, It just proved that at the center of the atom rested A positively charged portion, and we know that portion is the nucleus.
Next, atoms are composed of protons, neutrons and electrons. Now yes, the atom is composed of the subatomic particles. Yes, electrons do orbit the nucleus. Rutherford knew that the nucleus itself were positive, but he wouldn't have known that there were neutrons embedded in it as well, because remember, neutrons possess no charge. There'd be no way of him knowing that they existed within the nucleus as well. So this is not true.
Protons are not evenly distributed throughout an atom. Now here this is true. Protons are not distributed evenly throughout an atom. Like Thompson's plum pudding model would have suggested. The gold foil experiment proved that at the center of the atom itself is where we have a concentration of those protons, so this would be the most accurate.
Finally, protons are about 1000 times lighter than electrons. This is also true. We know that the subatomic particles neutrons are the heaviest, followed by protons and then electrons would be the lightest. Also, if the center wore highly densed as we believed, we'd expect the protons to be much more heavy than the electrons themselves. So here only option C would be the correct choice.