The correct answer is D. A government website on space exploration
Step-by-step explanation:
Non-fictional sources are completely based on facts and objective evidence, this means, they accurately describe reality and natural phenomena. This occurs websites and other sources created by the government because these are based on scientific evidence. According to this, the non-fictional source the author more likely use is "A government website on space exploration" because this is the only non-fictional source from the options, and it is adequate to integrate realistic elements about space as this is the main point in the story.