user: Question: What are all types where registration is HB-OPU?
Columns: ['Type', 'Registration', 'Design', 'Construction', 'Service', 'Construction date', 'Conformity to original design', 'Interest', 'Number existing in Switzerland', 'Number existing worldwide', 'Status']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Roesgen EPR 301', 'HB-OIX', 'Switzerland', 'Switzerland', 'Switzerland', '1921–1945', 'Unmodified', 'Technical and historical', 'Unique', 'Unique', 'Airworthy']
SQL:

assistant: SELECT "Type" FROM "Table" WHERE "Registration" = 'HB-OPU';