To determine which product yields an irrational number, we can analyze the options provided.
- Option A: 9 ⋅ 3 = 27 (Rational number)
- Option B: 78 ⋅ 25 = 1950 (Rational number)
- Option C: 264 ⋅ 781 = 206784 (Rational number)
Since all the given products are the result of multiplying two integers, all of them yield a rational number, and there are no options provided which will yield an irrational number.
If the question intended for you to determine which products are irrational, the answer would be "none of the above" since all are rational.
If there was a typographical error in option D (implying there should be a value that yields an irrational product), please provide that option for further analysis.