Thomas Edison's employee W.K.L.Dickson innovated which one of the following technological standards for cinema?

A) 35mm gauge
B) sound on film
C) sound on disc
D) color film

35mm Gauge

A standard film gauge most commonly used for both analog photography and motion pictures, measuring 35 millimeters in width.

Sound on Film

A process where audio is recorded onto the same strip of film as the images, synchronizing sound and picture.

Color Film

A type of film that includes chemical elements for producing images in color, as opposed to solely in shades of gray (black and white films).