The correct answer is option 1, Agra. The Revolt of 1857, also known as the Indian Rebellion of 1857, was a major uprising against British colonial rule in India. While Agra is a historically significant city, it was not a significant center of the Revolt of 1857.

Option 2, Kanpur, was indeed an important center of the revolt. It was here that the famous Siege of Kanpur took place, with Indian rebels fighting against British forces. Similarly, option 3, Jhansi, was also a prominent center of the revolt. It was the stronghold of Rani Lakshmibai, who played a crucial role in the rebellion.

Option 4, Lucknow, was another significant center of the revolt. The Siege of Lucknow is considered a historic event of the rebellion, with Indian rebels defending against British forces for a long period.

Therefore, the correct answer is 1 - Agra.