Question: During an ongoing call, what is the outcome of entering `2` followed by `SEND`, considering there are existing active calls?
Option 1: Releases all active calls and accepts the waiting call.
Option 2: Places all active calls (if any exist) on hold and accepts the other (held or waiting) call.
Option 3: Adds a held call to the current conversation, merging them.
Option 4: Disconnects the subscriber from all calls, including held ones.
Explanation: Entering `2` followed by `SEND` manages multiple calls efficiently. This action does not release or merge calls but rather holds existing active calls, allowing acceptance of another (either held or waiting) call, supporting effective call management in scenarios with multiple simultaneous calls.