user: Question: Name the frequency with class of B
Columns: ['Call sign', 'Frequency', 'City of license', 'Facility ID', 'ERP / Power W', 'Height m ( ft )', 'Class']
Types: ['text', 'text', 'text', 'real', 'real', 'text', 'text']
Sample row: ['WMHI', '94.7 FM', 'Cape Vincent, NY', 40435.0, 5800.0, 'm (ft)', 'A']
SQL:

assistant: SELECT "Frequency" FROM "Table" WHERE "Class" = 'B';