Question

Select the letter-cluster from among the given options that can replace the question mark (?) in the following series. PRT, OQS, NPR, ?

• A. GAS
• B. MJS
• C. GHA
• D. MOQ

Answer 1

Answer:

D. MOQ

Observe each position separately:

Term	1st Letter	2nd Letter	3rd Letter
PRT	P	R	T
OQS	O	Q	S
NPR	N	P	R
?	M	O	Q

Each letter decreases by one alphabet position in every step:

• P → O → N → M

• R → Q → P → O

• T → S → R → Q

Therefore, the missing letter-cluster is:

$\boxed{\text{MOQ}}$

Answer: MOQ.