which function does the merge parameter specify?

In the command, save config from tftp 1.1.7.250 abcd.cfg merge, which function does the merge parameter specify?

A.
The config file from the TFTP server will be combined with the configuration file in RAM and the combined result will be saved in internal flash.

B.
The config file from the TFTP server will replace the startup configuration file in internal flash.

C.
The config file from the TFTP server will replace the configuration in RAM.

D.
The merge parameter is not valid for TFTP files, it is only valid for configuration files stored in internal flash.