On a P-V diagram of an ideal gas, suppose a reversible adiabatic line intersects a reversible isothermal line at point A. Then at a point A, the slope of the reversible adiabatic line (? P /? V ) s and the slope of the reversible isothermal line (? P /? V ) T are related as (where, y = C p / C v )

• A. (? P /? V ) S = (? P /? V ) T
• B. (? P /? V ) S = [(?P/?V) T ] Y
• C. (? P /? V ) S = y (? P /? V ) T
• D. (? P /? V ) S = 1/ y (? P /? V ) T