user: Question: What is the call sign for country station FM 93.1?
Columns: ['Frequency', 'Call sign', 'Branding', 'Format', 'Owner']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['FM 88.9', 'CKYL-FM-5', 'YL Country', 'country', 'Peace River Broadcasting']
SQL:

assistant: SELECT "Call sign" FROM "Table" WHERE "Format" = 'country' AND "Frequency" = 'FM 93.1';