The Theoretical Forward Rate Implied by the Interest Rates and Spot

The theoretical forward rate implied by the interest rates and spot exchange rate can be expressed as ________.

A)
$\mathrm{S}=\mathrm{F}\left(\frac{1-\mathrm{i}_{\mathrm{A}}}{1+\mathrm{i}_{\mathrm{B}}}\right)$

B)
$\mathrm{F}=\mathrm{S}\left(\frac{1+\mathrm{i}_{\mathrm{A}}}{1-\mathrm{i}_{\mathrm{B}}}\right)$

C)
$F=S\left(\frac{1+i_{A}}{1+i_{B}}\right)$

D)
$F=S\left(\frac{1-i_{A}}{1-i_{B}}\right)$