Correct option is D
Given: "QZDH" → "51"

Find the positional values of each letter in the alphabet:
17+26+4+8=55
Subtract 4 to get 51:
55−4=51
Analyze "PLMQ" → "54"
16+12+13+17=58
Subtract 4 to get 54:
58−4=54
Apply the Pattern to "DNRB"
4+14+18+2=38
Subtract 4 to get the code:
38−4=34
Correct answer: the for "DNRB" is (d) 34.