CREATE TABLE table_51880 ("D 41" TEXT, "D 42" TEXT, "D 43" TEXT, "D 44" TEXT, "D 45" TEXT, "D 46" TEXT, "R 54" TEXT, "R 53" TEXT, "R 52" TEXT, "R 51" TEXT)

Name the D 42 which has a D 46 of r 26
SELECT "D 42" FROM table_51880 WHERE "D 46" = 'r 26'
SELECT "D 42" FROM "table_51880" WHERE "D 46" = 'r 26'