The correct option is
A be based on facts
Option A: A report's function is to convey information. Hence it should be based on facts. The same way, one must conclude the report based on facts. Hence option A is correct.
Option B: When a report's purpose is to recommend, then it ends with recommendations. If the purpose of the report is to give information about something or someone, then the recommendation isn't required. Hence this option isn't suitable.
Option C: The report is written for the reader, and by the writer. Hence, the reader's opinion cannot be recorded by the writer.
Option D: The conclusion can end by restating the event, or summarizing it. But, it shouldn't summarize it. Also, it's not necessary (should) to end a report with a restatement.
Hence options B, C and D are wrong.