Two reversible expansion curves start from the same initial point on a PV diagram for an ideal gas. Curve A is noticeably steeper than Curve B as both move toward larger volumes and lower pressures. Which statement best explains what Curve A represents compared with Curve B?
(a) Curve A is an isothermal expansion because its slope is steeper than that of an adiabatic expansion represented by Curve B.
(b) Curve A is an isobaric expansion because the pressure remains nearly constant, whereas Curve B is isothermal.
(c) Curve A is an adiabatic expansion because its slope is steeper than that of the isothermal expansion represented by Curve B.
(d) Curve A is an isochoric expansion because the volume is effectively constant, whereas Curve B is adiabatic.