Which of the following commands is used to change options and positional parameters for a running Bash?

`history` is used to display or manipulate the command history list, not shell options or parameters.

The `set` command is a Bash built-in that allows users to modify shell options, such as `set -o noclobber` to prevent overwriting files, and to assign or display positional parameters like `$1`, `$2`, etc. These changes directly affect the behavior of the currently running Bash shell.

`bashconf` is not a standard Bash command for configuring a running shell.

`setsh` is not a standard Bash command for altering shell settings.

`envsetup` is not a standard Bash command used to change shell options or parameters.