Question: Give the cohort name for the school with biggest cohort size.
SQL: SELECT DISTINCT T1.chronname FROM institution_details AS T1 INNER JOIN institution_grads AS T2 ON T2.unitid = T1.unitid WHERE T1.cohort_size = ( SELECT MAX(T1.cohort_size) FROM institution_details AS T1 INNER JOIN institution_grads AS T2 ON T2.unitid = T1.unitid )