Question

select the misplaced or dangling modifier. considered by many to be the first example of a motion picture, british photographer eadweard muybridge displayed a series of successive photographic images—a filmstrip of sorts—of a running horse in 1878.

Explanation:

A dangling modifier occurs when a modifier (here, "Considered by many to be the first example of a motion picture") doesn't clearly modify the intended word. The phrase should modify the "series of successive photographic images" (the motion - picture - like display), not "British photographer Eadweard Muybridge".

Answer:

Considered by many to be the first example of a motion picture