CREATE TABLE table_41398 ("Player" TEXT, "Club" TEXT, "League" FLOAT, "FA Cup" FLOAT, "FA Trophy" FLOAT, "League Cup" FLOAT, "Total" FLOAT)

Which League Cup has a FA Cup of 5, and a Club of boston united, and a League smaller than 16?
SELECT MAX("League Cup") FROM table_41398 WHERE "FA Cup" = '5' AND "Club" = 'boston united' AND "League" < '16'
SELECT MAX("League Cup") FROM "table_41398" WHERE "Club" = 'boston united' AND "FA Cup" = '5' AND "League" < '16'