CREATE TABLE table_77993 ("Name" TEXT, "Location" TEXT, "Length in km  ( mi ) " TEXT, "Year Completed" TEXT, "Line" TEXT)

Which line is the Geumjeong tunnel?
SELECT "Line" FROM table_77993 WHERE "Name" = 'geumjeong tunnel'
SELECT "Line" FROM "table_77993" WHERE "Name" = 'geumjeong tunnel'