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_24418525_1 ( callsign VARCHAR, coverage VARCHAR )

### Question ###
when coverage is dumaguete central visayas region, what is the callsign?

### Accurate SQL ###

SELECT callsign FROM table_24418525_1 WHERE coverage = "Dumaguete Central Visayas Region"