In a certain code, FOLDER is written as GMLECR. Using the same pattern, how is MARKET written?

Correct — A.
Rule: +1, −2, 0, repeated on each block of three letters.

FOLDER → GMLECR:
F + 1 = G, O − 2 = M, L + 0 = L
D + 1 = E, E − 2 = C, R + 0 = R

MARKET:
M + 1 = N, A − 2 = Y (A → Z → Y), R + 0 = R
K + 1 = L, E − 2 = C, T + 0 = T → NYRLCT, option (a).

Why the others are wrong

• (b)
  OZRLCT — OZ at the start moves M forward two and A back one. The rule is +1 then −2, which gives N and Y.
• (c)
  NYTLCR — T and R have traded places. The rule leaves the 3rd and 6th letters unchanged, so R stays third and T stays last.
• (d)
  NYRCLT — C and L are in the wrong order. K + 1 = L is the 4th letter and E − 2 = C the 5th, so L comes before C.

Letter-shift codes move each letter a set number of places. Find the move at each position, then look for a cycle: here +1, −2, 0 runs over FOL and again over DER.

A backward shift from the start of the alphabet wraps around: A − 1 = Z, so A − 2 = Y. That wrap is what separates NYRLCT from OZRLCT.

Key facts

• Backward shifts wrap past A: A − 1 = Z and A − 2 = Y.
• The cycle here is +1, −2, 0, repeating every three letters.
• A shift of 0 leaves a letter in place: L and R survive unchanged in FOLDER → GMLECR.

Common traps

• Stopping at Z for A − 2 instead of wrapping on to Y
• Missing the 0 shift and moving R and T as well

No directly related past PYQ was found.