The statement that best evaluates why Constantine I converted to Christianity during his fight to gain control of the Roman Empire is:
A) Constantine thought he saw a cross in the sky the night before a big battle and believed this celestial clue helped him win the battle.
This statement refers to the well-known vision of the Cross of Christ that Constantine reportedly experienced before the Battle of Milvian Bridge in 312 AD, which he interpreted as a sign of divine support for his cause. This moment was pivotal in his eventual conversion to Christianity and his support for the faith as he sought to unify and strengthen his rule over the empire.