CREATE TABLE table_68207 ("Heat" FLOAT, "Lane" FLOAT, "Name" TEXT, "Nationality" TEXT, "Time" TEXT)

In heat 4, what is Byun Hye-young's Nationality?
SELECT "Nationality" FROM table_68207 WHERE "Heat" = '4' AND "Name" = 'byun hye-young'
SELECT "Nationality" FROM "table_68207" WHERE "Heat" = '4' AND "Name" = 'byun hye-young'