Use a three-step tree to value an American put futures option when the futures price is 50,

Question:

Use a three-step tree to value an American put futures option when the futures price is 50, the life of the option is 9 months, the is 50, the risk-free rate is 3%, and the volatility is 25%.
Strike Price
In finance, the strike price of an option is the fixed price at which the owner of the option can buy, or sell, the underlying security or commodity.