The correct option is A Winding the wires of an alloy viz, manganin, constantan, nichrome
Wire bound resistors are made by winding the wires of an alloys, viz, manganin, constantan, nichrome etc. The choice of these materials is directed mostly by the fact that their resistivity's are relatively insensitive to temperature. These resistances are typically in range of a fraction of an ohm to a few hundred ohms.