In an oscillating spring mass system, a spring is connected to a box filled with sand. As the box oscillates, sand leaks slowly out of the box…

In an oscillating spring mass system, a spring is connected to a box filled with sand. As the box oscillates, sand leaks slowly out of the box vertically so that the average frequency $\displaystyle \omega(t)$ and average amplitude $\displaystyle A(t)$ of the system change with time $\displaystyle t$. Which one of the following options schematically depicts these changes correctly?