A thin, circular wire loop of radius \(R\) lies in the \(xy\)-plane centered at the origin and carries a steady current \(I\) in the counterclockwise direction when viewed from the positive \(z\)-axis. The loop is placed in a uniform external magnetic field \(\vec{B}_0\) that lies in the \(xz\)-plane and makes an angle \(\theta\) with the positive \(z\)-axis, where \(0 < \theta < 90^\circ\). Which of the following expressions represents the magnitude of the net magnetic field at the center of the loop?