In this task, you're given a statement, further information available on a particular linked term from the statement, and a question. Your job is to generate the answer to the question by using the information provided. If there is no clear answer obtainable, output 'none'.
Q: Context: During Sherman's Atlanta Campaign in 1864, his Army Group was composed of the Army of the Tennessee, the Army of the Cumberland, and the Army of the Ohio. Link Information:

It appears that the term "Army of the Tennessee" was first used within the Union Army in March 1862 Question: Which of Sherman's Army Groups were the oldest?
A:
Answer: The Army of the Ohio