Samuel was sent to Bethlehem to anoint a king from the sons of which man?

Answer: Jesse

The LORD said, "Fill your horn with oil and go. I am sending you to Jesse of Bethlehem, for I have selected from his sons a king."

“Now the LORD said to Samuel, “How long are you going to mourn for Saul, since I have rejected him as king over Israel? Fill your horn with oil and go. I am sending you to Jesse of Bethlehem, for I have selected from his sons a king for Myself.””— 1 Samuel 16:1 (BSB)