Professionals and the wealthy only did photography until George Eastman launched a new company called Kodak in the 1880s. Eastman created a flexible roll of film that did not necessitate continually changing the solid plates. This film gave him the liberty to create a self-contained box camera that held 100 film exposures. The camera had a little single lens with no focusing modifications.
The consumer would take pictures and send the camera to the factory where the film is developed and prints. This process is comparable to modern disposable cameras, and this was the first affordable camera in which most people could purchase. Before that, the cameras were not so readily available.
The incidence that put the camera into the forefront was pictures of World War I by working photographers. They were like nothing the public had ever seen before. They were gritty and real. From that point on, cameras were incorporated in the media and in general.
The answer to this is photography. Photography used to be something that people thought would be just a trend. Over time, people have realized that having photographs would mean having memories of the times that they can consider to be important such as a family event.
There was even a time when people were photographed only when they were already dead. Over time, people have realized that there are different ways to take photographs. Film photographs became popular before, and developing shops also thrived decades ago. As time became more modern, taking pictures has become far much easier as compared to how it was in the past.
The sentence starts with a series of phrases and a comma. After the blank there is what could be a verb and its object. This means we need the main subject and possibly the other part of the verb.
1. It is not letter (A) because it is only a verb.
2. It is not letter (B) because it would create a question in the sentence we have.
3. It is not letter (C) because it does have a connector at the end.
4. It is letter (D).