Which of the following number always divides the difference

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Which of the following number always divides the difference between the square of two consecutive odd numbers ?

1. 7
2. 3
3. 8
4. 6

Correct Option: C

Let the two consecutive odd numbers be 2x+1 and 2x + 3 .
∴ Difference = ( 2x + 3 )² - ( 2x + 1 )²
= ( 2x + 3 + 2x + 1 )( 2x + 3 - 2x - 1 )
=( 4x + 4 ) x 2
= 8 (x + 1)
whis is exactly divisible by 8.