Question: What is the primary implication for terminals regarding the 'blnk' (Blinking text) request in Timed Text Format for PSS?
Option 1: Terminals must support blinking text and adhere to a standardized blink rate.
Option 2: Terminals are not required to support blinking text, but if supported, must follow a specified blink rate.
Option 3: The decision to support blinking text is terminal-dependent, as is the method and rate of blinking.
Option 4: Blinking text support is mandatory for all terminals, with the blink rate determined by the network.
Explanation: This option correctly reflects the flexibility given to terminals in handling 'blnk' requests. Since terminals are not obligated to support blinking text, and if they do, both the achievement method and blink rate are left to the terminal's discretion, highlighting the terminal-dependent nature of this feature.