Fourletter-clusters have been given, out of whichthree are alike in some manner and oneis different. Select the odd letter-cluster.

G + 1 $$\rightarrow$$ H + 2 $$\rightarrow$$ J + 2 $$\rightarrow$$ M + 2 $$\rightarrow$$ P
A + 1 $$\rightarrow$$ B + 2 $$\rightarrow$$ D +3 $$\rightarrow$$ G +4 $$\rightarrow$$ K
B + 1 $$\rightarrow$$ C + 2 $$\rightarrow$$ E + 3 $$\rightarrow$$ H + 4 $$\rightarrow$$ L
N + 1 $$\rightarrow$$ O + 2 $$\rightarrow$$ Q +3 $$\rightarrow$$ T +4 $$\rightarrow$$ X
Option A has the unique operation so 'GHJMP' is odd.
$$\therefore$$ The correct answer is option A.