$(c)$ Consider a call option $onUS$ dollar with the strike price $x=0\mathrm{.}78$ pounds $toaUS$

dollar maturing $at$ time $1$ assuming $S(0)=0\mathrm{.}76$ and one step binomial model with

$S(1)=\{\begin{array}{ccc}0\mathrm{.}80& \text{w}\text{i}\text{t}\text{h}\text{t}\text{h}\text{e}\text{p}\text{r}\text{o}\text{b}\text{a}\text{b}\text{i}\text{l}\text{i}\text{t}\text{y}& p\\ 0\mathrm{.}75& \text{w}\text{i}\text{t}\text{h}\text{t}\text{h}\text{e}\text{p}\text{r}\text{o}\text{b}\text{a}\text{b}\text{i}\text{l}\text{i}\text{t}\text{y}& 1-p.\end{array}$

Suppose that the return after $1$ step $on$ investment $inGB$ pounds $is{K}_{}=5\%,$

and return $on$ investment $inUS$ dollars $is{K}_S=3\%.$ Using the replicating portfolio

method find the call option price.