The seal of all the prophets was Prophet Muhammed (S.A.W.).
In Islamic belief, Prophet Muhammed (S.A.W.) was the last and final messenger of Allah (God), sent to guide humanity to the right path. Muslims believe that he was chosen by Allah to convey His message to all people and to be the perfect example of how to live a righteous life.
The term "seal of the prophets" means that Prophet Muhammed (S.A.W.) is the last in the line of prophets that were sent by Allah to guide humanity. Muslims believe that he is the seal because he completed and perfected the message of Allah that was delivered by all the previous prophets, such as Abraham, Moses, and Jesus, among others.
Therefore, the answer to the question is Prophet Muhammed (S.A.W.), who is considered the seal of all the prophets in Islamic belief.