PL/SQL :: Finding The Maximum Truncate (date)

I've the following data set

with t as
(
select 1 cor_id , 'SR' rt_cd,TO_Date( '05/12/2010 01:12:19 PM', 'MM/DD/YYYY HH:MI:SS AM') dt,100 iss_id from dual union all
select 2 cor_id , 'SL' rt_cd,TO_Date( '05/12/2010 01:12:18 PM', 'MM/DD/YYYY HH:MI:SS AM') dt,100 iss_id from dual union all
select 3 cor_id , 'SR' rt_cd,TO_Date( '04/10/2010 02:11:15 PM', 'MM/DD/YYYY HH:MI:SS AM') dt,100 iss_id from dual union all
select 4 cor_id , 'SL' rt_cd,TO_Date( '04/10/2010 01:12:18 PM', 'MM/DD/YYYY HH:MI:SS AM') dt,100 iss_id from dual
)
select t1.*
from t t1for each iss_id =100 ,

there could me more than one record in the above data set, The requirement is i need to get the records where the trunc(dt) is maximum

I need to get 2 records with cor_id= 1 and 2.

how can i get those records