gerund?

[demoskopico]

The growth of the railroads led to the abolition of local times, which was determined by when the sun reached the oberver'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 oberver's meridian and differing
(B) which was determined by when the sun reached the oberver's meridian and which differed
(C) which were determined by when the sun reached the oberver'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

[kevin]

Eliminate (A) and (B) for their use of 'was'
(C) would be correct if it said "differed", preferably preceded by "which"
(D) lacks parallel structure

(E) correctly uses two participial adjectives, the first passive and the second active


Choose the correct participial adjectives below:

(Composing/Composed) of 48 states and (spanning/spanned) four time zones, the continental US is home to more than 300 million people