Consider a binomial tree model in which the length of each time step is 3 months. The annualized volatility of the underlying asset, which pays no dividends, is 0.3. The risk-free rate is 10% per annum (continuously-compounded). What is the risk neutral probability of an upward price movement in this model (up to the precision of two digits after the decimal point)?

a) .45

b) .5

c) .55

d) none of the above