What is intensity of electric field in the depletion region of which $2.5 \times 10^{-7} m$ if the potential barrier is $0.50 v$

Question

$(a)\;1 \times 10^6 \;vm^{-1} \\ (b)\;2 \times 10^{6} \;vm^{-1} \\ (c)\;1 \times 10^{-5}vm^{-1} \\ (d)\;2 \times 10^{+5} Vm^{-1}$