Answer:
A. To build tension and suspense.
H.G. Wells uses the term "the Thing" to refer to the Martian spacecraft in his novel "The War of the Worlds". This is done to build tension and suspense in the story, as the unknown and mysterious nature of the spacecraft adds to the overall sense of fear and uncertainty that the characters and readers experience. By not giving the spacecraft a proper name or clear description, Wells emphasizes the alien and threatening nature of the Martian invasion.