The tftpdnld command in Cisco IOS is specifically designed for recovering or upgrading a system image. Here's how it's the most effective method:
Purpose: The tftpdnld command directly initiates a TFTP download of a new system image and stores it in memory. This is ideal for replacing a corrupt image or upgrading to a newer version of Cisco IOS.
ROMmon: The tftpdnld command can often be used from ROMmon mode, which is essential when the existing image is unusable.
Efficiency: It streamlines the image transfer process specifically using TFTP, which is commonly used for Cisco IOS images.
Why other options are less ideal:
USB storage: While some newer Cisco devices may allow direct loading of an IOS image from USB, this isn't universally supported and often requires specific boot commands.
FTP: FTP (File Transfer Protocol) can be used for file transfers, but it's not as commonly used as TFTP in the context of Cisco IOS image recovery. The tftpdnld command offers a more tailored solution for this purpose.
the xmodem command: XMODEM is a legacy file transfer protocol that is slower and less reliable than TFTP, especially for larger files like Cisco IOS images.

Reference:
https://www.cisco.com/c/m/en_us/techdoc/dc/reference/cli/n5k/commands/show-environment.html

The commands to copy a saved configuration to RAM on Cisco devices are:
copy startup-config running-config: This command is used to copy the startup configuration (saved configuration) into the running configuration (current configuration in RAM). It is typically used when you want to restore the device to a previously saved configuration after changes have been made1.
copy tftp running-config: This command allows you to copy a configuration file from a TFTP server directly into the running configuration of the device. It's useful for applying a new configuration or for restoring a configuration from a backup located on a TFTP server1.
The other options listed are not valid for copying a saved configuration to RAM:
copy running-config startup-config copies the current running configuration to the startup configuration, which is the opposite of what's asked.
copy running-config tftp is used to save the running configuration to a TFTP server, not to copy to RAM.
copy tftp startup-config would copy a file from a TFTP server to the startup configuration, not to the running configuration in RAM.

Section: Cisco IOS Software Operation

The cmd program, also known as the Command Prompt, is the primary command-line interface in Windows. It allows you to execute various commands, including the ping command, to perform network testing and troubleshooting.
Here's how to use ping in the Command Prompt:
Open the Command Prompt: Search for 'cmd' in the Windows Start Menu or use the Run dialog (Windows key + R) and type 'cmd'.
Type the ping command: Enter ping followed by a space and then either the IP address or hostname you want to test. For instance: ping 8.8.8.8 or ping www.google.com.
Press Enter: The Command Prompt will send ping requests and display the results.
Why other options are incorrect:
Find: The Find utility in Windows is used to search for files and folders based on their content or attributes.
Start: The Start Menu in Windows provides access to programs, settings, and power options.
ipconfig: The ipconfig command is used to display network configuration information but doesn't directly execute the ping command.
Reference:
Windows Command Prompt (cmd): https://en.wikipedia.org/wiki/Cmd.exe
Ping command: https://en.wikipedia.org/wiki/Ping_(networking_utility)