Answer :
The answer is that he was able to defend the church. Over time, he began to observe his surroundings, and he was able to make his ideas more convincing.
The question concerns Saint Augustine's life in North Africa after the conversion to Christianity. He became a priest there although he wanted to become a bishop. Augustine set goals for remove the obstacles Orthodox Church faced. His efforts destroyed the Donatist claims. Augustine's next goal was to defend the Christianity in connection with the fall of Roman Empire. He defended his claims with his seminal work collected under the name "City Of God".
The correct answer is the first option.