To solve this, we need to calculate the center of mass of the remaining portion after cutting the square out of the circular disc. First, calculate the area of the square and find its center of mass. Then, by subtracting the area of the square from the disc, we can calculate the new center of mass of the remaining portion.
The center of mass of the remaining portion will be at a distance \( \frac{R}{4\pi - 2} \) from the center of the original disc. Thus, the correct answer is (A).