An X-ray photon with initial wavelength \(\lambda_0\) moves along the positive \(x\)-axis and collides with an electron initially at rest. The photon scatters at an angle of \(90^\circ\) relative to its initial direction of motion, as illustrated in the vector momentum diagram. In terms of Planck's constant \(h\), electron mass \(m_e\), speed of light \(c\), and initial wavelength \(\lambda_0\), which of the following expressions represents the magnitude of the momentum transferred to the electron?