2019 Pascal Problem 9

In the diagram, each partially shaded circle has a radius of 1 cm and has a right angle marked at its centre. In \text{cm}^2, what is the total shaded area?

\textbf{(A)}\ 4\pi^2\quad \textbf{(B)}\ 9\pi^2\quad \textbf{(C)}\ 4\pi\quad \textbf{(D)}\ 9\pi\quad \textbf{(E)}\ 3\pi

If there are no answer choices shown, enter a numerical answer.

Full credit to this problem is given to the CEMC, you may view all Pascal contests here.