Final answer:
The email subject line that would most likely be sent to a public works department is 'There is a Pothole on Walnut Street'.
Step-by-step explanation:
The email subject line that would most likely be sent to a public works department is There is a Pothole on Walnut Street. This subject line relates directly to the responsibilities and duties of a public works department, which typically includes maintaining and repairing roads and infrastructure.
The other email subject lines - 'Late Mail Delivery', 'Neighbor Stealing Mail', and 'My Neighbor's Burning Yard Waste' - are not directly related to the responsibilities of a public works department.
Learn more about Email subject line for public works department