Answer
$(A)~1.25\times 10^7~\Omega$
Work Step by Step
We can find the resistance of the person footwear as follows:
$I=\frac{\mathcal{E}}{R+R_{pf}}$
Where $R_{pf}$ shows the resistance of the person and footwear.
This simplifies to:
$R_{pf}=\frac{\mathcal{E}}{I}-R$
We plug in the known values to obtain:
$R_{pf}=\frac{50.0V}{3.7\times 10^{-6}A}-10^6\Omega$
$R{pf}=12.5\times 10^6\Omega$
$R_{pf}=1.25\times 10^7\Omega$
