simple insurance strategy

You wish to insure a portfolio for 1 year. Suppose that S = $100, s = 30%, r = 8%, and d = 0. You are considering two strategies. The simple insurance strategy entails buying one put option with a 1-year maturity at a strike price that is 95% of the stock price. The rolling insurance strategy entails buying one 1-month put option each month, with the strike in each case being 95% of the then-current stock price.
a. What is the cost of the simple insurance strategy?
b. What is the cost of the rolling insurance strategy? (Hint: See the previous problem.)
c. Intuitively, what accounts for the cost difference?