Which of the following is an example of a public auction?

A public auction is defined as one where the items being auctioned are available for purchase by any member of the public, not restricted to a private group. A government surplus sale represents the sale of items that are no longer needed or have been surplus to government requirements, and it is typically open to the public. This type of auction allows anyone to participate and bid on the items, which can range from vehicles to office equipment, making it a clear example of a public auction.

In contrast, the other choices either involve private sales or specific target groups. A garage sale is typically a private event held by an individual or family to sell their personal belongings and is not conducted in a formal auction setting. A charity auction can be open to the public, but it usually serves a specific cause and may have tickets or entry fees, limiting access. An estate sale is often a private sale of personal property from a deceased person's estate, where bidding may not be conducted publicly in the same manner as a traditional auction. Thus, the nature of a government surplus sale distinctly categorizes it as a public auction.