$($a$)(1$ pts$)$ Social Security Numbers $($SSNs$)$ in the United States are typically formatted as nine digits separated by hyphens in the following format: area$-$group$-$serial where area is a $3-$dirit number from

$100-999$ and group is a number from $11-99$ and serial is a number from $0001-9999.$ Write a regex that is able to identify all SSN$\text{'}$s in a document.