According to put-call parity, shorting a call option on a stock while longing a put option with the same maturity and strike price is equivalent to: (a) Buying a put option, selling the stock, and investing the proceeds at the risk-free rate. (b) Buying a put option and buying the stock with funds borrowed at the risk-free rate. (c) Longing a forward contract. (d) Shorting a forward contract.