A portion of an embankment having a uniform up-gradient 1 in 500 is circular with radius 1000 m of the centre line. It subtends 180° at the centre. If the height of the bank is 1 m at the lower end, and side slopes 2:1, the earth work involved.

• A. 6,000 m³
• B. 6,500 m³
• C. 7,000 m³
• D. 7,500 m³