retrieve duplicate value from linq

Hi all,

I have some issue with linq statement. here is my table, named Tblactivity

activityid bigint
studentid bigint
activitydate datetime
description nvarchar(Max)
status bit

i populate Tblactivity with data. such as

activityid | studentid | activitydate | description | status
1 | 1 | 2012-08-15 00:30:00 | descA | A
2 | 3 | 2012-08-16 12:30:00 | descAA | A
3 | 2 | 2012-08-16 13:15:12 | descB | B
4 | 3 | 2012-09-02 10:20:11 | descS | A
5 | 3 | 2012-09-02 11:00:00 | descS | A
6 | 4 | 2012-09-02 14:00:00 | descAA | S

so i develop linq to get detail information of student id = 3. here is my linq code

public List<Tblactivity> getStudents(long studentid, string status)
   {
	studentdatacontext db=new studentdatacontext;
            try
            {
                List<Tblactivity> BG = (from o in db.Tblactivities
                              orderby o.activitydate descending where o.studentid == studentid &&  
                              o.activitydate.Value.Month <= DateTime.Now.Month &&
                              o.activitydate.Value.Month >= DateTime.Now.Date.AddMonths(-1)&&
                              o.status == status select o).ToList();

                return BG;
            }
            catch (Exception e)
            {
                throw e;
            }
        }

so i got all of the records according to student id = 3.but i want only one record when the activitydate is same (the latest record).
i read some article they suggest me to use MAX(). but i don't know how to develop to suit with the above function. pls suggest me.

Thanks,
df

Tags: C#, Visual Basic, .NET, LINQ, ASP.NET, MVC3