How are the children selected for twelve giver?

The book "The Giver" by Lois Lowry does not specify a process for selecting children for the role of the Receiver of Memories. In the dystopian society depicted in the story, it is clear that the government exerts significant control over all aspects of citizens' lives and assigns crucial duties based on perceived suitability and qualifications. As the book primarily focuses on the main character, Jonas, who is chosen as the Receiver of Memories, specific details about the selection process remain undisclosed. Therefore, I cannot answer the question based solely on the information provided in the source material.