The graph illustrates how resistance $R$ changes as the length $l$ of two wires X and Y, both made from the same material, varies. What is shown by the graph?
- Across-sectional area of X = $2 \times$ cross-sectional area of Y
- Bresistivity of X = $2 \times$ resistivity of Y
- Cwhen equal lengths of X and Y are connected in series to a battery, power in X = $2 \times$ power in Y
- Dwhen equal lengths of X and Y are connected in parallel to a battery, current in X = $2 \times$ current in Y