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

Answer: Option A

This question asks about how to get rid of indexes in MySQL, which are like shortcuts that help your database find data faster.
Think of an index like the table of contents in a book - it helps you quickly find the information you need.
Option A: DROP INDEX is the correct answer. It's the command used to delete an index from a table.
Option B: DELETE INDEX is incorrect. This command is not used to remove indexes.
Option C: REMOVE INDEX is also incorrect. There is no command called "REMOVE INDEX" in MySQL.
Option D: FLUSH INDEX is incorrect. This command clears the index cache, which is different from removing the index itself.
So, the answer is Option A: DROP INDEX.