问题如下：
Given the fc llowing parameters for a firm, what is the value of the firm's equity?
• Asset value of $180.
• Risk-free rate of 5%.
• $100 par value debt with a 7% coupon, maturing in one year.
• A European put option worth $1.50 on the firm's assets with a strike price equal to the face value of debt.
选项：
A.$74.00.
B.$74.52.
C.$79.20.
D.$79.72.
解释：
D The film’s equity can be calculated as Et = At - Dt. We can value Dt using the Merton model:
Dt = De-rT - (European put value with strike at D) = $107 x e-0.05*1 - $1.50 = $100.28 We can then calculate Et:
Et = At - Dt = $180 - $100.28 = $79.72.
请问这里公式中的D`代表的是最后到期时的面值吗？
