A cart of mass \(M\) is attached to an ideal horizontal spring with spring constant \(k\). A small block of mass \(m\) is placed on top of the cart, as shown. The coefficient of static friction between the block and the cart is large enough that the block does not slip relative to the cart. The system is pulled a distance \(A\) from its equilibrium position and released from rest on a horizontal frictionless surface. Which of the following expressions represents the magnitude of the maximum acceleration \(a_{\text{max}}\) of the block as it oscillates?