Answer:
The correct answer to the question is
a. it contradicted accepted principles of physics
Step-by-step explanation:
The idea of electrons moving in orbits contradict classical electromagnetism idea whereby electrons are expected spiral to the nucleus instantaneously. Meaning all atoms are supposed to be unstable a postulation that contradicts observable evidence.
Bohr's model of the atom consists of atoms, having electrons in specific orbits. The theory explains spectroscopy and enabled the determination of the constituent atoms present in distant stars.