In the alphanumerical series D-4, F-6, H-8, J-10, ?, ?, which two terms should replace the question marks to continue the pattern?

Introduction / Context:
This question presents an alphanumerical series, meaning each term is made up of a letter and a number tied together by a consistent rule. You must identify the pattern in both the letter part and the number part to determine the missing entries. Such series are typical in reasoning sections of many competitive exams.

Given Data / Assumptions:
- The given terms are: D-4, F-6, H-8, J-10, ?, ?- Each term combines a capital letter with an even number.- We assume the letter progression and number progression each follow simple arithmetic patterns.

Concept / Approach:
To solve alphanumerical series, separate the two components: the letter sequence and the number sequence. Treat each as its own series, identify the pattern independently, and then pair the appropriate letter and number to form the missing terms. In many such questions, letters move in fixed steps and numbers increase by a constant amount.

Step-by-Step Solution:
- For letters: D, F, H, J correspond to positions 4, 6, 8, 10 in the alphabet.- The pattern is an arithmetic progression with a common difference of +2.- Therefore, the next two letters after J (10) are: 12 (L) and 14 (N).- For numbers: 4, 6, 8, 10 form another arithmetic progression with a difference of +2.- The next two numbers will be 12 and 14.- Pairing these results gives the missing terms: L-12 and N-14.

Verification / Alternative check:
- Check full combined series: D-4, F-6, H-8, J-10, L-12, N-14.- Letters move by +2 positions each time (D, F, H, J, L, N).- Numbers also increase by +2 each step (4, 6, 8, 10, 12, 14).- The pattern is perfectly consistent throughout the sequence.

Why Other Options Are Wrong:
- K-12 or K-14 would come from position 11, which does not match the +2 pattern starting from D (4).- Any combination not using L and N breaks the arithmetic sequence in the letters.- Number pairs like 12, 14 are correct, but they must be attached to the correct letter sequence.- Only L-12, N-14 preserves both the letter and number patterns simultaneously.

Common Pitfalls:
Candidates sometimes focus solely on the numerical part and ignore the letter logic, or vice versa. Others miscalculate alphabet positions, particularly if they do not mentally index the letters from A to Z. Writing down positions explicitly (A = 1, B = 2, ..., Z = 26) can prevent such mistakes.

Final Answer:
The two missing terms in the series are L-12 and N-14, so the correct option is L-12, N-14.