A student measures the terminal potential difference (V) of a cell (of emf $\epsilon$ and internal resistance r) as a function of the current (I) flowing through it. The slope and intercept of the graph between V and I, then, respectively, equal

• A

  $\mathrm{\epsilon }\mathrm{and}-\mathrm{r}$

• B

  $-\mathrm{r}\mathrm{and}\mathrm{\epsilon }$

• C

  $\mathrm{r}\mathrm{and}\text{\hspace{0.17em}\hspace{0.17em}-}\mathrm{\epsilon }$

• D

  $-\mathrm{\epsilon }\mathrm{and}\mathrm{r}$