A. a battle journal written by an officer of the Confederate army
Explanation:
A battle journal written by an officer of the Confederate army would be the most reliable source to collect and transmit information on the Civil War.
Journals are records which are actually written during the time the action was taken place. So, a Confederate army putting down the experiences of a Civil War will be reliable because he is writing out of his experiences. Journals are credible because you can verify the facts from their original sources as well as it is enriched with facts and truths. Journals offer clarity.
