Alana Boyd of group B with a 4.30 result has what nationality?
CREATE TABLE "qualifying_round" (
  "group" text,
  "name" text,
  "nationality" text,
  "4_00" text,
  "result" text
);
SELECT "nationality" FROM "qualifying_round" WHERE "group"='b' AND "result"='4.30' AND "name"='alana boyd';