There is a square field of side \(500\,\text{m}\) long each. It has a compound wall along its perimeter. At one of its corners, a triangular area of the field is to be cordoned off by erecting a straight-line fence. The compound wall and the fence will form its borders. If the length of the fence is \(100\,\text{m},\) what is the maximum area that can be cordoned off?
A. \(2,500 \,\text{sq m}\)
B. \(10,000 \,\text{sq m}\)
C. \(5,000 \,\text{sq m}\)
D. \(20,000 \,\text{sq m}\)
E. \(7,500 \,\text{sq m}\)
OA A