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:

The opening participial phrase "Considered by many to be the first example of a motion picture" is intended to describe the series of photographic images, not Eadweard Muybridge. Since it incorrectly modifies the photographer instead of the work, it is the misplaced/dangling modifier.

Answer:

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