Question: What does the `<state>` value of `2` indicate when using the `+CBKLT` AT command to control the backlight of a User Equipment's (UE) main display?
Option 1: Enable the backlight for a short duration specified by the UE manufacturer.
Option 2: Enable the backlight indefinitely.
Option 3: Disable the backlight.
Option 4: Enable the backlight for a specified period of time (in seconds) set by the user.
Explanation: According to the `+CBKLT` parameter command syntax, setting the `<state>` value to `2` specifically means enabling the backlight indefinitely. This contrasts with other options that either specify a short duration (set by the manufacturer), a user-specified duration, or disabling the backlight altogether. In practical telecom scenarios, understanding such nuances is crucial for effectively managing device resources and user experience.