Chapter 8.3, Problem 14MS

DeceptIve dice (ExH). You asked three friends to do an experiment while you were out of the room. Two of them each tossed a fair die 40 times and recorded the results. The third friend generated a sequence of 40 digits from 1 to 6 with an effort to make it look like the random results of tossing an actual die. You return to see the results below. Which sequences do you think came from tossing an actual die? Why?

$\begin{array}{l}\text{a}\text{. 2263544462325266213314341115432513326512}\hfill \\ \text{b}\text{. 53416342162534162332541 16235425614256313}\hfill \\ \text{C}\text{. 5625162316144634623333266251365164624536}\hfill \end{array}$