The option is D. Word order.
One of the most difficult things about translating an original text is keeping the word order. The order a sentence is said in english for example is very different from the order in spanish. For example the sentence:
"I live in a beautiful white house", in spanish this would be
"Yo vivo en una hermosa casa blanca"
The position of white and blanca is different. If the translator doesn´t change the word order then the sentence would be translated as:
"Yo vivo en una hermosa blanca casa" which is structurally incorrect in spanish.