Final answer:
The implied continuously compounded risk-free interest rate is approximately 9.808%, which can be rounded to 10%(option d).
Step-by-step explanation:
To calculate the continuously compounded risk-free interest rate, we can make use of the put-call parity formula:
C - P = S - K * e^(-rt)
Where C is the price of the call option, P is the price of the put option, S is the current stock price, K is the strike price, r is the continuously compounded risk-free interest rate, and t is the time to expiration.
Plugging in the given values:
2 - 5 = 40 - 45 * e^(-r * 0.5)
Simplifying the equation:
-3 = -5e^(-0.5r)
Dividing both sides by -5:
0.6 = e^(-0.5r)
Taking the natural log of both sides:
ln(0.6) = -0.5r
Dividing both sides by -0.5:
r = -ln(0.6) / 0.5 ≈ 0.9808
Converting to a percentage:
r ≈ 0.9808 * 100 ≈ 9.808%
Therefore, the implied continuously compounded risk-free interest rate is approximately 9.808%, which can be rounded to 10%.