The odd man out in this set of options is C) zbej.
In this problem, we are presented with four choices of sets of letters, all of which have a pattern; however, we must identify the pattern that is different from the others.
(a) fhko
In this pattern, the first letter skips 1 letter to receive the second (f ⇒ h). To get the third letter, the second letter skips 2 (h ⇒ k). Then, to get the fourth letter, the third letter skips 3 (k ⇒ o).
(b) cehl
This pattern follows the same sequence as did option A. To get the second letter, the first letter skips 1 (c ⇒ e). To get the third letter, the second letter skips 2 (e ⇒ h). Then, to get the fourth letter, the third letter skips 3 (h ⇒ l).
(c) zbej
This pattern seemingly follows the same as options A and B until the last letter (j). To get from z to b, 1 letter (A) is skipped (z ⇒ b). To get from b to e, 2 letters are skipped (b ⇒ e). To get from e to j, we must skip 4 letters (e ⇒ j).
(d) xzcg
This pattern abides by the same foundations of options A and B. To get from x to z, one letter (Y) is skipped (x ⇒ z). To get from z to c, two letters (A and B) are skipped (z ⇒ c). Finally, to get from c to g, three letters (D, E, and F) are skipped (c ⇒ g).
With all patterns aside from option C representing the same patterns, we find that option C is the odd one out.