Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_80 ( opened INTEGER, system VARCHAR, daily_ridership VARCHAR )

### Question ###
Which Opened has a System of c-train, and a Daily ridership smaller than 269,600?

### Accurate SQL ###

SELECT MAX(opened) FROM table_name_80 WHERE system = "c-train" AND daily_ridership < 269 OFFSET 600