Choose the correct alternative answer

$m....nm....n.....an.....a....ma.....$

Study the following arrangement carefully and answer the question.
$O, 4, E, J, 5, T, 1, A, M, Q, 3, 8, N, I, K, 7, W, F, 6, S, 9, U, 2, Y, X$
Which of the following is the sixth to the left of the eleventh from the left end of the above arrangement?

Find the missing letters for the given series from the given alternatives:
$.....abb......\,,....bb....a.....bbab.....ba$

Find the missing term for the given series from the given alternatives.
$G, H, J, M, (?), V$

What should come next in the following number sequence?
$2, 2, 3, 2, 3, 4, 2, 3, 4, 5, 2, 3, 4, 5, 6, 2, 3, 4, 5, 6, 7, 2, 3, 4$

Choose the correct alternative to complete the series: $a...abbb...cccd....ddccc....bb...ba$