The statement used to remove indexes on tables is . . . . . . . .

This question asks about how to get rid of indexes on a table in MySQL. Indexes help your database find information quickly, but sometimes you might need to remove them.

Let's look at the options:

Option A: DROP INDEX - This is the correct answer! You use `DROP INDEX` to delete an index from a table.

Option B: DELETE INDEX - This is incorrect. `DELETE` is used to remove rows from a table, not indexes.

Option C: REMOVE INDEX - This is also incorrect. MySQL doesn't have a command called `REMOVE INDEX`.

Option D: FLUSH INDEX - This is incorrect. `FLUSH INDEX` is used to refresh the index cache, not delete indexes.

So, the answer is Option A: DROP INDEX.