Almost-bipartite distance-regular graphs with the $Q$-polynomial property

Let $G$ denote a $Q$-polynomial distance-regular graph with diameter $D$ at least 4. Assume that the intersection numbers of $G$ satisfy $a_i=0$ for $0 \leq i \leq D-1$and$a_D\neq 0$\mathrm{.}Weshowthat$G$ is a polygon, a folded cube, or an Odd graph.