A user complains that their smartphone battery drains significantly faster than usual, despite normal usage patterns. They have not installed any new applications recently and the device is relatively new. What is the FIRST action you should take to troubleshoot this issue?
Identify if any applications are using high amounts of resources.
Check for any pending OS updates and ensure the system is up to date.
Replace the battery with a new one.
Directly disable Bluetooth and Wi-Fi to save battery life.