user: Question: Who was on the prohibition ticket when the Greenback ticket had Thomas Armstrong?
Columns: ['Office', 'Democratic ticket', 'Republican ticket', 'Prohibition ticket', 'Greenback ticket']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Governor', 'Lucius Robinson', 'Edwin D. Morgan', 'William J. Groo', 'Richard M. Griffin']
SQL:

assistant: SELECT "Prohibition ticket" FROM "Table" WHERE "Greenback ticket" = 'Thomas Armstrong';