Writing and Reading

      From the latter half of the 19th century until nearly the middle of the 20th, one of the easiest ways for the average American to obtain a portrait photograph was by approaching a booth at a fair or commissioning an itinerant or street photographer. The process, from posing for the camera to a finished portrait in hand, required only a matter of minutes. And it was inexpensive, costing only a few cents for a likeness of oneself, or perhaps of a child or sweetheart.
      It’s easy to understand why someone would be interested in such a portrait, as it could be created with minimal equipment on any busy street corner. The metal base (iron, not tin, despite the name) for the photo was far more durable than paper, and so it offered a lasting photographic record…

Which choice provides the most logical transition into the next paragraph?