SELECT SUM (x) FROM R; COMMIT Betty's transaction is a sequence of inserts: INSERT INTO R VALUES (10); INSERT INTO R VALUES (20); INSERT INTO R VALUES (30); COMMIT Carol's transaction is a sequence of deletes: DELETE FROM R WHERE x=30; DELETE FROM R WHERE x=20; COMMIT; Before any of these transactions execute, the sum of the integers in R is 1000, and none of these integers are 10, 20, or 30. If Alice's, Betty's, and Carol's transactions run at about the same time, and each runs under isolation level READ COMMITTED, which sums could be produced by Alice's transaction?