What facts are being used in this atomic structure question? I wish to understand how to solve this atomic structure question:


  For the ground state, the electron in the H-atom has an angular
  momentum = $\hslash$ , according to the simple Bohr model. Angular
  momentum is a vector and hence there will be infinitely many
  orbits with the vector pointing in all possible directions. In
  actuality, this is not true, because:



Bohr model gives incorrect values of angular
momentum.
only one of these would have a minimum energy.
angular momentum must be in the direction of spin of electron.
electrons go around only in horizontal orbits.


Actually, we have been taught Bohr orbits a lot in class, with formulae for everything (atomic radius/electron orbital speed/various energy levels/etc.)  and also basics of the quantum mechanical model. However, we didn't go into such a great depth of Bohr orbits as asked in the above question. 

Specifically, I don't know of any reasonable arguments against points 1,2,3. Point 4 is evidently wrong based on the quantum mech model.


  How do I develop any claim for/against the points 1,2,3? What are the facts involved here?
The only correct answer is #1.  

In actuality, the ground state of the hydrogen atom has zero angular momentum.  

Regarding #2 and #4, there is no preferred plane in which one point should orbit another point.  By symmetry, they are all equivalent.  

Regarding #3, there is no angular momentum in the ground state, and in a state whether there is angular momentum, it doesn't need to be in the same direction as the electron spin angular momentum.