A thin, rigid wire carries a constant current \(I\) and is bent to form a closed flat loop in a plane. The loop consists of a semicircle of radius \(R\) and a straight wire segment of length \(2R\) along the diameter connecting the endpoints of the semicircle. Point \(P\) is located at the center of curvature of the semicircle. Which of the following expressions represents the magnitude of the magnetic field at point \(P\)?