Classifying solvable primitive permutation groups of low rank

Suppose that a finite solvable permutation group G acts faithfully and primitively on a finite set Ω. Let G0 be the stabilizer of a point α∈Ω and the rank of G be the number of distinct orbits of G0 in Ω (including the trivial orbit {α}). Then G always has rank greater than four except for in a few cases. We completely classify these cases in this paper.