Which example represents a semi-detached house?

A semi-detached house is characterized by two houses that share a common wall but are otherwise separate structures. This type of house typically features similar architectural designs and is often found in residential neighborhoods.

In this case, choosing Dylan O's house implies that it is one half of a structure that is shared with another house, correctly identifying it as a semi-detached home. Semi-detached houses provide advantages such as a smaller footprint and the potential for shared utilities or landscaping, making them an appealing option for many homeowners.

To further clarify, while the other options represent different types of homes, they do not feature the defining characteristic of a semi-detached house, which is the shared wall with an adjacent unit.