Tesla stock is traded at $400, and its volatility is 30% per annum. The risk-free rate is 5% per annum (continuously compounded). A trader is considering shorting a 6-month at-the-money European put option on Tesla stock.

A) What is the strike price of the put option?

B) Use the Black-Scholes-Merton model to calculate the put option price.

C) Calculate the delta of this option.

D) The trader wants to use option delta to evaluate his exposure on Tesla stock. If put options delta is -0.1 and contract size is 100 shares per contract, then shorting one put option is approximately equivalent to long or short (choose one) how many Tesla shares?