Today is t = 0 and there are 2 possible states next year (t = 1), either s = bust or s = boom. Risky asset A and the safe asset generate the following payoff.

States (s)	bust	boom
Asset A	$y - a	$y + a
Safe asset	$1	$1

Suppose that there are two call options of asset A expiring in t = 1: a bust call option and a boom call option. They have the strike price at K_bust = y - a and K_boom = y + a, respectively.

In each state s, what is the payoff of portfolio that buys one unit of the bust call option and short one unit of the boom option? Payoff combination in (bust, boom) is

(a,a)

(-a,a)

(0,a)

(0,2a)

None of the above