Which of the following is not an automatic variable in PowerShell?

Which of the following is not an automatic variable in PowerShell?

• $Matches
• $Last
• $args
• $Error 

EXPLANATION

While there are automatic variables for the last cmdlet executed, the last argument used in that cmdlet, and the exit status (False if it threw an error; True if it didn't), there is no automatic variable that represents the last full command, or the last command's output.  $Last is not an automatic variable in the shell.
$Error is an array that's populated by all errors output in the current session (by default, up to 256 errors, although this can be changed by changing the value in $MaximumErrorCount).
$args is an array containing any command line arguments that were passed to a function or script; it's only usable from within that function or script.  Typically, this is not used as "param()" is a lot more powerful and typically easier to work with.
$Matches is an array containing the results of the last match with regular expressions against a string.  Note that it does not get populated if the match was performed against an array; in that case, -match just outputs the matching items directly to output.