Answer:
f(n) = 2 + 3(n-1)
Step-by-step explanation:
The range of the piecewise function would be from [2,infinity), or the second choice.
1/6*1/6*1/6*1/6 = 1/1296 = 0.078% probability of ANY 4-letter sequence (including qqqq)
1000/1296 is less than 1.
Expected number of times qqqq (or any given 4-letter sequence) will appear in 1000 letters is 0.
Putting all points in equation of option B satisfies the table, so the answer is option B