Analyzing False Statements about Orbitals

[a.a]

I was able to work through most of them myself but am haveing problems with the following, for some I simply don't understand the statement it self. Any help appericiated.
Pick the false statements out of the following:


a. Different p orbitals with the same value of the principal quantum number have different orientations in space.
b. Only three different orientations are possible for 3d orbitals.
c. A dxy orbital has maximum electron density along the x and y axes directions.
d. For the hydrogen atom, a 3d orbital is of higher energy than a 4s orbital.
e. For helium atom, a 3d electron is of higher energy than a 3s electron.

I think b, c, and d are false, but am very unsure.

 

[a.a]

I just read-up on the topic a bit more, I now think that only b and c are false. Can someone pleasr verify?