In the script script.sh, how should MYVAR be set to make it display its content?

To ensure that the variable MYVAR is available to subshells and external programs invoked from the script, it must be exported to the environment. Setting a variable in shell scripting ordinarily makes it accessible only within the current shell or script. However, by using the export command, MYVAR is marked for export to the environment, allowing any subprocess that the script spawns to access the variable's value.

When MYVAR is set with "export MYVAR=value," it creates an environment variable that retains its value even in child processes, which is essential for scripts that rely on passing information between different layers of execution. This is particularly useful in scenarios where the script calls other programs or scripts that need to access the information stored in MYVAR.

The other options either do not provide the necessary visibility outside the current context or are not valid syntax for defining environment variables in a shell environment. For instance, the option for setting MYVAR without export makes it local, while using "define" is not a recognized command in the shell for setting variables. Thus, the requirement for MYVAR to display its content effectively in subshells and external commands hinges on using the export command.