Pattern matching questions

I saw the below questions and was curious regarding the logic behind the answer. I will be grateful is some one could help me

So the question is given the patter, identify the next one

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By looking at the directions of the arrows and their heights, I'd say E :) – Alex Oct 20 '12 at 8:06
Denying a relation between the even and odd elements of the sequence leads to D as a sensible choice. The change of orientation of the arrows indicates that one of D and E should be the answer. – Lord_Farin Oct 20 '12 at 8:56
Are you sure this has something to do with maths, and isn't some cop-out such as "how to dance the Timewarp"? – Douglas S. Stones Oct 20 '12 at 11:29
As @DouglasS.Stones mentioned at math.stackexchange.com/questions/217888/…, this question seems to be from europa.eu/epso/application/passport/… – Joel Reyes Noche Oct 21 '12 at 10:12