Kenneth Arrow is famous, in part, for his "impossibility theorem." Which of the belowbest describes the sense of "impossibility" at work in the theorem:

a) It should be impossible for any individual to hold intransitive preference orderings.

b) It is impossible for Condorcet methods to avoid preference cycles with certainty.

c) It should be impossible to restrict the domain of potential individual preferences orderings.

d) It is impossible for any method meant to generate a social choice out of individual preferences to satisfy five simple and reasonable restrictions.