If you are not able to find the Developer options after updating to Android 4.3 in your Xperia (mine is a Xperia M ), then do the following:
In your phone open “Settings” page, then click on “About phone” scroll down to “Build Number” and keep tapping on it until you get the message “You are now a developer”. 🙂
Now, Go to Settings and then scroll all the way down, and just above “About Phone” you would see “Developer Options”and click on it.
Click on it. Then Make sure the top “Developer options” is selected, and then check the option “USB Debugging”.
Then click on “OK“.
Finally, you will have :
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