To find the relationship between the letter-clusters, let's analyze the transformation: MDT -> PAW RFQ -> UCT The transformation seems to involve shifting each letter by a fixed number of positions in the alphabet: M -> P (+3) D -> A (-3) T -> W (+3) Similarly, R -> U (+3) F -> C (-3) Q -> T (+3) So, applying the same pattern to LSK: L -> O (+3) S -> P (-3) K -> H (-3) Thus, the answer is option 3: OPN
13, 26, 104, ?, 13312, 425984
6 55 91 116 132 ? .
D irection: Which of the following will replace ‘?’ in the following series
9, ‘?’, 1242, 1581, 1783
...52 26 39 97.5 ?
...5, 11, 19, 29, 41, ?
4, 8, 24, ?, 840, 9240
620 632 608 644 596 ?
...210 211 207 223 159 ?
...130 114 106 102 100 ?
7 14 42 168 840 ?
...