Answer:
b) line spectra
Step-by-step explanation:
The model of the atom as given by Rutherford was modified by Bohr. According to Rutherford's model, the electrons that orbit the nucleus electromagnetic radiation. As a result they lose energy and had to collapse into the nucleus, thereby making the atom unstable.
Bohr corrected that by proving that electrons revolve around the nucleus only in certain fixed orbits, with a specific energy. They can jump from one to another and lose or gain energy by emitting or absorbing energy in that process.
Electron cloud is the region where the electrons are most likely to occur. This was proposed by Schrodinger.