A square pond has 2 m sides and is 1 m deep. If it is to be enlarged, the depth remaining the same, into a circular pond with the diagonal of the square as diameter as shown in the figure, then what would be the volume of earth to be removed?

1. (a)(2π − 4) m³
2. (b)(4π − 4) m³
3. (c)(4π − 2) m³
4. (d)(2π − 2) m³