Photoelectric effect (AP Chemistry question)
I think the teacher pointed out that (c) is the correct answer because the postulate is generally regarded as incorrect according to the normal convention of photons behaving as individual packets of energy. 

However what I think is interesting is that more than one electron can be ejected provided the photon is sufficiently energetic (this information will not be useful during an examination, so I suggest forgeting about this when you take an exam or do your homework, but if interested read on). For more information you can search for "multielectron ejection in auger spectroscopy" which provided references [1] and [2] below. Reference [2] opens up with the following statement: 


  Absorption of an energetic photon by a target should in first approximation lead to the ejection of one electron only, as this interaction is purely mono-electronic. However it is well established that sometimes several electrons can be ejected. This can happen in valence multiple ionization or after innershell ionization when secondary electrons are emitted sequentially (cascade Auger decays) or simultaneously (direct double Auger decays). Such processes and especially the ‘one-step’ or direct ones (direct double ionization or direct double Auger decay) are extremely interesting to investigate as they revealthe strongelectron correlation phenomena which are at their origin.  


Not sure what Einstein would have thought of this in any case.

An Auger process does not violate the principle that intramolecular electronic transitions are quantized and therefore that the energy required to eject electrons is quantized, irrespective of the number ejected. So the first two postulates are still correct.

References


P. Lablanquie, M.A. Khalal, L. Andric, J. Palaudoux, F. Penent, J-M Bizau, D. Cubaynes, K. Jänkälä, Y. Hikosaka, K. Ito, K. Bučar, M. Žitnik, Multi-electron coincidence spectroscopy: Triple Auger decay of Ar 2p and 2s holes,
Journal of Electron Spectroscopy and Related Phenomena, Volume 220, 2017, Pages 125-132, https://doi.org/10.1016/j.elspec.2017.04.003.
https://pure.mpg.de/rest/items/item_737492/component/file_737491/content