False. "Crumb" is not a type of pie crust, but rather a type of topping that can be used on pies or other desserts. A crumb topping typically consists of flour, sugar, and butter that are mixed together until crumbly and then sprinkled over the top of a fruit or custard filling before baking. Pie crusts, on the other hand, are typically made from flour, fat (such as butter or shortening), salt, and water, and are rolled out and fitted into a pie dish before being filled and baked.