The underlined portion includes the verb have traced, so check for subject-verb agreement. The subject is historians, so the plural verb have traced is correct. (The prepositional phrase "of film" ends in a singular noun to trick you into thinking that the verb should be singular.) The idiom "trace something to" is correctly used. Since there is no error evident in choice A, hold onto it for now and check out the other choices.

In choice B, the word order is changed, but it is not an improvement. The main issue is that the prepositional phrase in 1913 doesn't modify film, which is what the logic dictates; instead, in 1913 seems to modify called, which lacks sense. Worse yet, it could also be construed as part of the title of the short - A Noise from the Deep in 1913! Eliminate B.

Choices C and D use the singular verb has traced, creating subject-verb disagreement. Eliminate both.

Choice E changes the meaning. The film historians aren't tracing the "pie in the face" gag itself (which may have occurred in non-film contexts) but its appearance in film. The phrase to its first appearance in a 1913 short implies, without much sense, that the gag was traced to its first use in a particular film short, implying that it was used more than once in the same film. Eliminate E and stick with A, the correct answer.