For simplicity take n = 6 ..

Sum of first 6 consecutive terms = 6x +15

Now say x = 2 or x = 5 each time the sum is a multiple of 9 but the sum os not even Hence we get no ..hence it is sufficient

I still dont get it...what does x stands for?

1) For this statement we need to know that an odd number + another odd number = an even number, and an odd number + an even number = an odd number. If n = 6, that means there are 3 pairs of an odd and an even number. When we sum up each of the three pairs, we have 3 odd numbers. When we sum up the 3 odd numbers, we have an odd number.

2) I think this statement means if we take all the numbers and use them as digits to form 1 number, then that number is a multiple of 9. For example, 9, 45, 234, etc, fit the criteria. We also know for a number to be a multiple of 9, the sum of its digits must equal 9, which is an odd number.

Therefore the answer is D.

Thanks a lot Argen! I did not understand what statement 2 could possibly mean....