An option where the holder has the right to choose whether it is a call or a put at some point during its E(Rit) characteristic line E(Rmt) life. This prespecified date is normally called the choice date. The chooser options can either be a standard simple chooser option or complex chooser option. The former refers to both call and put specified with same price and maturity time. The latter refers to call price and maturity date different from those of put option.