Sentence Correction

Q. The growth of the railroads led to the abolition of local times, which was determined by when the sun reached the observer’s meridian and differing from city to city, and to the establishment of regional times.
(A) which was determined by when the sun reached the observer’s meridian and differing
(B) which was determined by when the sun reached the observer’s meridian and which differed
(C) which were determined by when the sun reached the observer’s meridian and differing
(D) determined by when the sun reached the observer’s meridian and differed
(E) determined by when the sun reached the observer’s meridian and differing

OA is [spoiler](E)[/spoiler]. Why not [spoiler](D)[/spoiler]?

Thanks,
Rohit.

please mark the underlined portion accordingly