Two identical batteries having emf 2.4 V and internal resistance 0.5$\Omega$ are connected as shown. Potential Difference between A and B is

Question

 

$\begin {array} {1 1} (a)\;4.8V & \quad (b)\;2.4V \\ (c)\;1.2V & \quad (d)\;None\: of \: these \end {array}$