The product of two consecutive positive integers CANNOT be
(A) a prime number
(B) divisible by 11
(c) a multiple of 13
(D) an even number less than 10
(E) a number having 4 as its units digit
The answer is the last option for a product to have 4 in its units place ,units place of muliples should be either of the following
1) 2&2
2) 1&4
3) 6&4
4) 8&3
5) 9&6
Since none of them can be consecutive numbers we have our answer.