Complete the alphabet series A, B, D, G, ?, P by choosing the option that correctly fills the missing term while maintaining the pattern of letter positions.

Introduction / Context:
This question presents an alphabet series with one missing letter: A, B, D, G, ?, P. The task is to determine the correct letter that fits into the series. This type of problem examines understanding of variable step size patterns in the English alphabet and prepares candidates for more complex series questions in reasoning tests.

Given Data / Assumptions:

• Series: A, B, D, G, ?, P.
• All terms are single uppercase letters.
• The pattern likely involves increasing forward jumps that change in a regular way.
• Options: I, J, K, L.

Concept / Approach:
The technique is to convert each letter into its numeric position and then observe the differences between consecutive terms. Often, alphabet series use increasing step sizes, such as +1, +2, +3, and so on. By identifying this pattern, we can compute the missing term and then confirm that it leads correctly to the final term P.

Step-by-Step Solution:
Step 1: Convert the letters to positions: A(1), B(2), D(4), G(7), ?, P(16).Step 2: Observe the differences between consecutive positions: from A(1) to B(2) is +1, from B(2) to D(4) is +2, and from D(4) to G(7) is +3.Step 3: The pattern so far is adding 1, then 2, then 3. It is natural to expect the next step to be +4.Step 4: Apply +4 to G(7). This gives 7 + 4 = 11, which corresponds to the letter K.Step 5: To verify further, continue the pattern by adding +5 after K. From K(11) plus 5 we get 16, which is P, the last letter of the given series.Step 6: This confirms a consistent pattern of increments: +1, +2, +3, +4, +5, leading to the sequence A(1), B(2), D(4), G(7), K(11), P(16).

Verification / Alternative check:
We can summarise the pattern as a series of triangular increments. The first difference is 1, the second is 2, the third is 3, the fourth is 4, and the fifth is 5. Calculating all terms using this rule reproduces the exact sequence that ends with P. None of the other options I, J, or L allows the final term P to be reached using a clean increasing step sequence of this form.

Why Other Options Are Wrong:
If we choose I(9) or J(10) as the missing term, adding a further larger step to reach P(16) would break the simple +1, +2, +3, +4, +5 pattern. Similarly, choosing L(12) would result in an incorrect starting position for the final step. Thus, these options are inconsistent with the elegant and regular increment scheme we identified.

Common Pitfalls:
Some learners may attempt to find a constant difference or may miscalculate the numeric values of letters. Others may jump directly to P without checking intermediate steps. Carefully writing the numeric positions and computing successive differences ensures that the correct pattern and missing letter are found without confusion.

Final Answer:
The missing letter in the series A, B, D, G, ?, P is K.