need the answer asap, please show work! thanks.

8. A stock is currently priced at $40. It is known that at the end of one month it will be either $38 or $42. The risk-free rate is 0.67% per month. The current value of a European call option with an exercise price of $39 is about: a. $0.27 b. $0.54 c. $1.10 d. $1.69 e. $2.44