For two call options on the same underlying asset and same time to maturity, the

relationship $c(K1)-c(K_2)K_2-K_1,$ for $K_1$ must hold. Otherwise, there

$isan$ arbitrage opportunity. Given the following option prices:

Among the four calls, there $is$ one pair for which the above relationship $is$ not hold and

thus, one can make arbitrage. $Todoso,$ one should buy option with strike price

and sell option with strike price

The minimum profit $is$

$,$ and

the maximum profit $is$