cfg merge, which function does the merge parameter specify?

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

A.
Theconfig file from the TFTP server will replace the configuration in RAM

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

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

D.
Theconfig file the TFTP server will be combined with the configuration file in RAM and the combined result will be saved in internal flash