In 1812, Dietrich Nikolaus Winkel invented the metronome, wh

[MichelleY103]

In 1812, Dietrich Nikolaus Winkel invented the metronome, which is a device that produces a regulated audible pulse usually used to establish a steady tempo for the performance of musical composition s
(A) which is a device that produces a regulated
(B) which is a device that produces a regular
(C) a device that produce a regulated
(D) which is a device that produce a regulated
(E) a device that produces a regulated

It is a question from GMAT the economist note. Sorry I'm not sure if I'm allowed to post here. Anyway, the answer is E. I choose A and see the part as Non-restrictive Attributive Clause modifies metronome, however they say A is more redundant than E. I'm not sure about that, and, is E appositive?
Thank you GMAT tutors in advance.

[Chelsey Cooley]

Would you mind reposting this one in the 'general verbal questions' folder? This one is for questions about MPrep problems that aren't in the CATs, i.e. strategy guide questions.