Prophet Muhammad (PBUH) performed only one Hajj in his lifetime after migrating to Madinah. This Hajj is famously known as the Farewell Pilgrimage (Hajj al-Wada), which took place in the 11th Hijri year.

Before the migration, the Prophet had visited Makkah several times for Umrah and other religious purposes, but this was his only full Hajj. During this pilgrimage, he gave his important Farewell Sermon, which laid down the foundations of justice and equality in Islam.

This Hajj is significant because it was the final pilgrimage the Prophet performed and serves as a practical example for Muslims to follow.

Understanding the number of Hajj performed by the Prophet helps students grasp important aspects of Islamic history and the timeline of his life.

Therefore, the correct answer is: One, referring to the sole Hajj performed by Prophet Muhammad (PBUH).