The output of the program date should be saved in the variable actdat. What is the correct statement?

The syntax actdat=`date` uses backtick command substitution, which executes the date command in a subshell and assigns its stdout as the value of actdat. Variable assignment in bash requires no spaces around the equals sign, and wrapping the command in backticks (or the equivalent $()) is the correct way to capture command output.

The set built-in modifies shell options or positional parameters, not named variables; additionally, 'date' in single quotes is treated as a literal string, not a command to execute.

The pipe operator passes the stdout of one command as stdin to the next command - it cannot assign output to a shell variable.

The > operator redirects output to a file, not into a variable; $actdat would expand to the current value of actdat as a filename rather than storing output into the variable.

Without backticks or $(), actdat=date assigns the literal string 'date' to the variable instead of the output of executing the date command.