OFFICIAL EXPLANATION
The Internet enables people who are thousands of miles apart to conveniently speak or otherwise contact each other.A. miles apart to conveniently speak or otherwise contact each
This answer choice is grammatically incorrect.
The verb speak requires a preposition in order to adequately connect to each other. People do not speak each other - they usually speak to or with each other.
What helps us identify this question as a Split Construction question and identify the mistake is the following Stop Sign:
A split construction: Verb A + and/or + Verb B + object
B. miles apart to conveniently speak or otherwise contact one
This answer choice repeats the original mistake.
In addition, this answer choice is not logical, meaning wise, as a result of replacing each with one. There's no such thing as one other (there's one another, which is not the same). Leaving only the words one other begs the question, "one other what??"C. miles apart to conveniently speak to or otherwise contact each
This answer choice corrects the original mistake by adding the required preposition to after the verb speak.D. miles apart to conveniently speak to or otherwise contact one
While this answer choice corrects the original Split Construction mistake, it is not logical, meaning wise, as a result of replacing each with one. There's no such thing as one other (there's one another, which is not the same). Leaving only the words one other begs the question, "one other what??"E. miles apart to conveniently speak to or make contact with each
While this answer choice corrects the original Split Construction mistake, it is stylistically flawed. Replacing the verb contact with the words make contact with creates overly wordy phrasing.
Also, omitting the word otherwise changes the meaning of the original sentence.