For a certain gas, pressure P (in kPa) depends on volume V (in L) by a differentiable, invertible function P=q(V). At V=2 L, P=100 kPa and dVdP=−40 kPa/L. Volume in turn depends on temperature θ (in ∘C) through a differentiable, invertible function V=r(θ) with r(300)=2 and dθdV=0.01 L/°C at θ=300∘C. What is dPdθ at P=100 kPa?
a) −0.025∘C/kPa
b) −0.4∘C/kPa
c) −2.5∘C/kPa
d) 2.5∘C/kPa