CREATE TABLE table_18350 ("District" TEXT, "Incumbent" TEXT, "Party" TEXT, "First elected" FLOAT, "Result" TEXT, "Candidates" TEXT)

what is the district with the candidates edward boland (d) unopposed?
SELECT "District" FROM table_18350 WHERE "Candidates" = 'Edward Boland (D) Unopposed'
SELECT "District" FROM "table_18350" WHERE "Candidates" = 'Edward Boland (D) Unopposed'