You have an investment that will pay you $100$ BTC $($bitcoin$)$ in $2$ years, if you invest $80$ BTC today. Assuming you want a return of $10\%,$ what is the NPV of this deal?

$20$ BTC

$3\mathrm{.}33$ BTC

$10\mathrm{.}91$ BTC

$2\mathrm{.}64$ BTC