The ∂ E ∂ T P of different types of half cells are as follows : A B C D 1 × 10 - 4 2 ×…

The ${\left(\frac{\partial \mathrm{E}}{\partial \mathrm{T}}\right)}_{\mathrm{P}}$ of different types of half cells are as follows :
$\begin{array}{cccc}\mathrm{A}& \mathrm{B}& \mathrm{C}& \mathrm{D}\\ 1\times {10}^{-4}& 2\times {10}^{-4}& 0.1\times {10}^{-4}& 0.2\times {10}^{-4}\end{array}$

(Where $\mathrm{E}$ is the electromotive force). Which of the above half cells would be preferred to be used as reference electrode