1- Consider a two-period binomial model, where each period is 6 months. Assume the stock price is $75.00, = 0.35, and r = 0.05. An American call option with a strike price of $80 would be exercised early at what dividend yield? (a) 5.0 % (b) 7.0 % (c) 9.0 % (d) Never exercise early Answer: D

2- Consider a two-period binomial model, where each period is 6 months. Assume the stock price is $50.00, = 0.20, r = 0.06 and the dividend yield = 3.5%. What is the lowest strike price where early exercise would occur with an American put option? (a) $50 (b) $55 (c) $60 (d) $65 Answer: C

3- Consider a two-period binomial model, where each period is 6 months. Assume the stock price is $60.00, = 0.30, r = 0.05. An American put option with a strike price of $65 would be exercised early at what dividend yield? (a) 5.0 % (b) 6.0 % (c) 11.0 % (d) Never exercised early Answer: D

I am looking for detail explanations for these three questions. Thank you very much for your help!