The lamp of flash light is 1 .5 $\mathrm{\Omega }$. It uses 3 cells each of 1 . 5 V and internal resistance 0 . 25 $\mathrm{\Omega }$. What is the net potential difference across the lamp ?

• A

  1.5 V

• B

  2.25 V

• C

  3 V

• D

  4.5 V