Which of the following terms will replace the question mark ($?$) in the given series?
AFM, DIP, GLS, ?

Let's analyze the alphabetical positional shifting pattern for each position in the letter-clusters:
1. First Letter:
A (1) $\stackrel{+3}{\to }$ D (4) $\stackrel{+3}{\to }$ G (7) $\stackrel{+3}{\to }$ J (10)
2. Second Letter:
F (6) $\stackrel{+3}{\to }$ I (9) $\stackrel{+3}{\to }$ L (12) $\stackrel{+3}{\to }$ O (15)
3. Third Letter:
M (13) $\stackrel{+3}{\to }$ P (16) $\stackrel{+3}{\to }$ S (19) $\stackrel{+3}{\to }$ V (22)

Combining these positions, the next term in the series is JOV.