Which of the following ensures that data segments are delivered in order?

When data is sent over a network, it is broken into small parts called segments. TCP numbers each segment before sending them. If the segments arrive out of order, TCP uses these numbers to rearrange them correctly at the destination.

This feature is very important for applications that require reliable and ordered communication, such as web browsing, email, and file transfers.

TCP also checks for lost or duplicate segments and makes sure nothing is missing. This is what makes TCP a reliable, connection-oriented protocol.

Conclusion: The correct answer is TCP. It ensures that data segments reach the receiver in the correct order, even if they are sent at different times.