Which statement is used to create a trigger?

Answer: Option A

This question is asking about how you create a special type of rule in MySQL called a trigger.
Triggers are like extra actions that happen automatically when something else happens in your database.
For example, you could set up a trigger to automatically send an email whenever a new customer is added to your database.

Now, let's look at the options:
Option A: CREATE TRIGGER - This is the correct answer! This is the command used to create a new trigger in MySQL.
Option B: CREATE TRIGGERS - While it's close, this is not the correct syntax. You use "CREATE TRIGGER" for a single trigger.
Option C: PRODUCE TRIGGER - This is not a valid command in MySQL.
Option D: PRODUCE TRIGGERS - This is also not a valid command in MySQL.

So the answer is Option A: CREATE TRIGGER.