=+24. (Chooser option). Let time moments T and s ∈ [0, T], a strike price K >

0 and a continuously compounded interest rate r be given. A chooser option is a contract sold at time t = 0 that gives its holder the right to choose at the time t = s either a call or a put which both expire at time t

= T and have the strike K. Using the put–call parity relation, show that at time t = 0 the price of a chooser option is the sum of the price of a put at time t = 0, which expires at time T and has the strike K, and the price of a call at time t = 0, which expires at time t = s and has the strike e

–(T–S)r K.