A small spacecraft of mass \(m\) in deep space is equipped with a flat solar sail of surface area \(A\). A monochromatic laser beam with peak electric field magnitude \(E_0\) shines normally onto the sail. The sail surface has a reflectivity coefficient \(R\), where \(R = 1\) represents complete reflection and \(R = 0\) represents complete absorption. Which of the following expressions correctly gives the magnitude of the initial acceleration \(a\) of the spacecraft in terms of \(m\), \(A\), \(E_0\), \(R\), and fundamental constants?