The term means that ip provides no error checking or tracking. ip assumes the unreliability of the underlying layers and does its best to get a transmission through to its destination, but with no guarantees

 "Best-Effort"

Explanation: The IP protocol is neither responsible for delivering packets to destination nor those packets arrive in the same order than they were transmitted, i.e., does the "Best Effort", that's all.

These functions are responsibility of the transport layer, like TCP in the TCP/IP Suite.

yes we can change both the color of the value of a cell as well as background color of a cell at the same time .

as we know that excel sheet consists of columns and rows.

and intersection of column and row is called cell.

we can change color of the cell and background of the cell at the same time.

hence the statement that

can a person change color of the cell and background of the cell at the same time is true.