Yes.
They have called the 5 numbers the factors. The means, the question is essentially asking,
In a product, 11 * 13 * 17 * 19 * 23, reducing which of the 5 factors by 1 (11 to 10, 13 to 12.... )reduces the product.
Option A: 11
11 * 13 * 17 * 19 * 23 is now 10 * 13 * 17 * 19 * 23
So reduction is the difference (11-10) 1 * 13 * 17 * 19 * 23
Option B: 13
11 * 13 * 17 * 19 * 23 is now 11 * 12 * 17 * 19 * 23
Difference: 11 * 17 * 19 * 23
If you see this number is smaller than the difference above. In all other choices.. difference will keep reducing.
Hence the answer.
Vineesh,
Just telling you what I know and think. I am not the expert.
