Rand function generates random numbers between 0 and 1 that are evenly spaced and the average of those numbers is the average of two extremes i.e. average of 0 and 1.
Average of 0 and 1 is 0.5. So the average of the random numbers generated will be very close to 0.5000
The average will vary from 0.5 when the generated numbers are few. But if we increase the numbers generated, their average will approach to 0.5.
So the answer to this question is option B