If the Stock Price Follows a Random Walk,successive Price Changes

Multiple Choice

If the stock price follows a random walk,successive price changes are statistically independent.If σ² is the variance of the daily price change,and there are t days until expiration,the variance of the cumulative price change is:

A) σ²
B) (σ²) × (t)
C) (σ²) /t
D) (σ) × (t²)