MC5: "Single-peakedness" in preference distributions (as discussed by Maskin) doesnotrefer to:

a) The expectation that each individual's preferences areideological, and can thus be arrayed in a linear way, with alternatives closer to the individual's ideal point being preferred to those further away from it.

b) The idea that not all preference orderings are likely to occur in reality.

c) A phenomenon which helps Condorcet methods avoid cycles.

d) Situations wherein a set of individual preference orderings can only be given a decisive social ordering by one voting method or aggregation rule.