A reversible adiabatic path, on a P-V diagram, for an ideal gas passes through state A where P = 1 MPa and V = 0.0025 m3. Given that the ratio of specific heats for the gas is 1.4, the slope of the path at A is
1
4 × 105 kPa/m3
2
-4 × 105 kPa/m3
3
-5.6 × 105 kPa/m3
4
5.6 × 105 kPa/m3