The correct answer is D. None of the above.
The train traveled 96 kilometers in 1 hour. Therefore, we do not need to use an article.
A, an, and the are all indefinite articles. Indefinite articles are used when we are referring to a general thing or person, not a specific one. In this case, we are not referring to a specific hour, so we do not need to use an indefinite article.
The definite article the is used when we are referring to a specific thing or person. In this case, we are not referring to a specific hour, so we do not need to use the definite article.