The Significance of the Battle of Saratoga Was That It

The significance of the Battle of Saratoga was that it

A) removed the Indian tribes from the fighting.
B) demonstrated the benefit of having that seasoned French officer, the Marquis de Lafayette, on the site of the patriots.
C) let the colonists know that winning the war might take a very long time.
D) convinced several European countries, most importantly the French, to join the patriots in their fight against Britain.
E) gave a bit of hope to the demoralized Continental Army.