During setup, what does iOS 9 prompt you (by default) to enter as a passcode?

During setup, what does iOS 9 prompt you (by default) to enter as a passcode?

• A 6-digit passcode
• An alpha-numeric passcode
• A 4-letter code
• A 4-number passcode 

EXPLANATION

 Apple is rolling out its new iOS 9 Wednesday and with that comes a big security upgrade.

The new operating system will now automatically default to a six digit PIN to unlock your device, instead of just a four digit PIN. While this might seem like a small change, it actually makes breaking into your iPhone a lot more difficult.

With a four digit PIN, there are a possible 10,000 combinations. But with a six digit code, there are 1 million possible combos, making it a lot tougher for someone to crack your security code.  

If you are currently using a four digit PIN and update your software, you will need to manually opt in for the six digit PIN.