d
A battery is of emf $E$ is being charged from a charger and hence current inside the cell is from anolde to cathode
$I=\frac{V-E}{I}$
$V=E+I r$
Therefore, when a cell is being charged the potential difference across its terminals is greater than emf of a cell. Also in charging the positive terminal is connected to anode of the cell and negative terminal to cathode.
Here, positive terminal of the battery is connected to terminal $A$ of charger and negative terminal of the battery is connected to terminal $B$ of charger.
Hence, Potential difference across points $A$ and $B$ must be more than $E$, $A$ must be at higher potential than $B$ and In battery, current flows from positive terminal to the negative terminal