With reference to settlement cycles in India's securities market, consider the following statements:
- T+0 settlement means that eligible trades are settled on the same day.
- The T+0 mechanism was introduced as an optional facility alongside the existing T+1 settlement cycle.
- T+0 settlement immediately replaced T+1 settlement for all listed securities.
- The initial beta implementation of T+0 was introduced for a limited set of securities and market participants.
Which of the statements given above are correct?