Cannot Convert bool? to bool

My code in my Data Layer DtbseDropDown = ii.DtbseDropDown is throwing an error and I am not sure how to get around it. The error says: "Cannot implicitly convert type 'bool?' to 'bool'. An explicit conversion exists (are you missing a cast?)"

Here are the code blocks for my Data Layer and my Entities

Data Layer

public static List<ListProjectTypes> GetListProjectTypes()

    {
        using (var context = new Sys.EntityModels.HousingRehabEntities())
        {
            // build and execute query against the db
            //return context.ListProjectTypes.Where(x => x.DtbseDropDown=true).ToList();

            // build and execute query against the db
            return (from ii in context.ListProjectTypes
                    where (ii.DtbseDropDown == true)
                    //&& ((ii.LastName + ii.FirstName + ii.Middle) != null))
                    ////&& ((ii.LastName) != null))
                    orderby ii.SortOrder
                    select new Sys.Entities.ListProjectTypes
                    {
                        ProjectType = ii.ProjectType,
                        SortOrder = ii.SortOrder,
                        DtbseDropDown = ii.DtbseDropDown


        }).ToList();

        }
    }
}

Entities

namespace CityOfMesa.HousingRehab.Sys.Entities
{

 public class ListProjectTypes
    {
        public string ProjectType { get; set; }
        public int? SortOrder { get; set; }
        public bool DtbseDropDown { get; set; }
    public ListProjectTypes()
    {

        ProjectType = string.Empty;
        SortOrder = 0;
        DtbseDropDown = true;

    }
}

}