-- Database schema
| AREA_CODE_STATE : area_code [ INT ] primary_key , state [ TEXT ] | CONTESTANTS : contestant_number [ INT ] primary_key , contestant_name [ TEXT ] | VOTES : vote_id [ INT ] primary_key , phone_number [ INT ] , state [ TEXT ] VOTES.state = AREA_CODE_STATE.state , contestant_number [ INT ] VOTES.contestant_number = CONTESTANTS.contestant_number , created [ TEXT ] |
-- -- What is the area code in which the most voters voted?

SELECT T1.area_code FROM area_code_state AS T1 JOIN votes AS T2 ON T1.state  =  T2.state GROUP BY T1.area_code ORDER BY count(*) DESC LIMIT 1;