Projection of mongodb subdocument using c# .net driver 2.0

I have the following structure:

public class Category
{
    [BsonElement("name")]
    public string CategoryName { get; set; }

    [BsonDateTimeOptions]
    [BsonElement("dateCreated")]
    public DateTime DateStamp { get; set; }

    [BsonElement("tasks")]        
    public List<TaskTracker.Task> Task { get; set; }
}

    public class Task
{
    [BsonElement("name")]
    public string TaskName { get; set; }

    [BsonElement("body")]
    public string TaskBody { get; set; }
}

I am trying to query a Category to get all the TaskName values and then return them to a list to be displayed in a list box. I have tried using this query:

var getTasks = Categories.Find<Category>(x => x.CategoryName == catName).Project(Builders<Category>.Projection.Include("tasks.name").Exclude("_id")).ToListAsync().Result;   

But what get returned is: {"tasks": [{"name: "test"}]} . Is there anyway to just return the string value?