Final answer:
The option that does not support the theory that some large elliptical galaxies are the product of galaxy collisions is E), which mistakenly claims that most galaxies are elliptical and thus incorrectly uses the commonality of galaxy collisions as evidence for elliptical galaxy formation.
Step-by-step explanation:
The argument that is not a strong argument for the theory that some large elliptical galaxies formed as the result of galaxy collisions is E) Galaxy collisions are common and most galaxies in the universe are elliptical. This assertion is incorrect because most galaxies in the universe are not elliptical; in fact, they come in a variety of shapes including spiral and irregular.
Moreover, just the frequency of galaxy collisions does not directly support that elliptical galaxies are a common result, as the merger process and resulting galaxy type are determined by specific conditions and events.
Observational evidence and computer simulations provide strong support for the scenario where large elliptical galaxies form from the mergers of smaller galaxies. For instance, the presence of stars and gas that rotate in opposite directions to the rest of the galaxy (Option B) indicates a tumultuous past likely involving the merging of galaxies with different orientations. The existence of star shells around some ellipticals (Option C) also supports this, as they can be remnants of past collisions and fusions.
Moreover, the predominance of elliptical galaxies in dense clusters (Option A) can be the result of frequent interactions and mergers in these environments. Also, the prediction by computer simulations that collisions generally result in elliptical galaxies (Option D) adds theoretical support to the observational evidence.