POST

All possible arrangement of letters :-
P ⇒ 59, 66, 78, 85, 97
O ⇒ 01, 13, 20, 32, 44
S ⇒ 03, 10, 22, 34, 41
T ⇒ 56, 68, 75, 87, 99
R ⇒ 04, 11, 23, 30, 42
A ⇒ 55, 67, 79, 86, 98
M ⇒ 02, 14, 21, 33, 40
As shown in given figure , all the values for word POST are matched in only option ( 3 ) for every letter . So , the set for the word POST will be 59, 01, 10, 99 .From matrix , option ( 3 ) is correct .