Pattern Analysis:

The given series of letters is ABJN, CDOE, EFUY, GHBK. To find the next term in the series, we need to analyze the pattern and identify the rule governing the sequence.

First Letter:
- The first letter of each term (A, C, E, G) follows an increasing alphabetical order with a difference of 2 letters.

Second Letter:
- The second letter of each term (B, D, F, H) also follows an increasing alphabetical order with a difference of 2 letters.

Third Letter:
- The third letter of each term (J, O, U, B) follows an increasing alphabetical order with a difference of 9 letters.

Fourth Letter:
- The fourth letter of each term (N, E, Y, K) follows an increasing alphabetical order with a difference of 4 letters.

Pattern Analysis Summary:
- The first and second letters follow an increasing alphabetical order with a difference of 2 letters.
- The third letter follows an increasing alphabetical order with a difference of 9 letters.
- The fourth letter follows an increasing alphabetical order with a difference of 4 letters.

Application of the Pattern:

Using the identified pattern, we can find the next term in the series.

First Letter:
- The next letter after G (the last letter in the given series) would be I.

Second Letter:
- The next letter after H (the last second letter in the given series) would be J.

Third Letter:
- The next letter after B (the last third letter in the given series) would be K.

Fourth Letter:
- The next letter after K (the last fourth letter in the given series) would be O.

Final Answer:
The next term in the series is IJKO.