What is the name of the southernmost county seal in West Virginia?

The correct answer is Welch, which is the seat of McDowell County and known for its southernmost location in West Virginia. Each county in the state has its own unique seal, which often symbolizes local history, culture, and resources. Welch, being the county seat of a historically significant area in southern West Virginia, represents the identity of the region effectively through its seal.

The other options represent cities located in different counties of West Virginia, but none of them are part of the southernmost county. Harpers Ferry is located in Jefferson County in the eastern panhandle, Martinsburg is a city in Berkeley County, and Wheeling serves as part of Ohio County in the northern region of the state. Thus, those choices do not reflect the southernmost geographical aspect that Welch does.