Answer:
A. 360
Explanation:
The factors of 6 on a fair six-sided die are 1, 2, 3, and 6.
Therefore, the probability of getting a factor of 6 on a single roll of a fair six-sided die is:

Since each roll is independent, the probability of getting a factor of 6 on each roll is always 2/3.
The expected frequency is calculated by multiplying the probability of an event by the number of trials.
We are told that when a die is rolled k times, the expected frequency of getting a factor of 6 is 240. Therefore:

Therefore, the value of k is 360.