Final Answer:
In what is now Saudi Arabia, Mohammed first announced himself as a prophet and launched the preaching mission that, by persuasion and conquest, came to control the region both spiritually and politically.
Step-by-step explanation:
In the early 7th century, Mohammed began his ministry in what is modern-day Saudi Arabia. He declared himself a prophet, initiating a religious movement that ultimately wielded significant influence over the Arabian Peninsula, both in matters of faith and governance. Initially centered in Mecca and later in Medina, Mohammed's preaching gathered followers and supporters through his persuasive teachings and, at times, through military conquests. His leadership laid the foundation for Islam, a religion that would spread across continents and profoundly impact the world's cultural, social, and political landscapes.
The significance of this historical event in the Arabian Peninsula underscores the pivotal role of Mohammed's announcement and the subsequent establishment of Islam, not only as a religious faith but also as a socio-political force that shaped the region's history.
Correct Answer: Saudi Arabia