What is a photograph?
a. an image created by light falling on a light sensitive surface, usually film.
b. a print in white on a blue ground, often used for copying maps, or architects plans.
c. a devise used to capture an image of a moment in time.
d. an inverted image transferred for a light-sensitive metal plate onto film.

a. an image created by light falling on a light sensitive surface, usually film.

Explanation:

     Photography is the technique of creating images by light exposure on a photosensitive surface.

    Chemists and physicists were the pioneers in this art, as the processes of photography development and fixation are essentially physicochemical, in a combination of environmental and lighting conditions with chemicals.

ive noticed that too but is this a question