In the incomplete letter pattern _BC_Q_AB_P_R, which one set of letters, when placed sequentially in the blanks, will complete the series correctly?

Introduction / Context:
This question presents a partially hidden series _BC_Q_AB_P_R where letters must be inserted into the blanks to obtain a logically consistent pattern. Such problems usually conceal a repetition of a simple segment of letters. The candidate must choose among the given options the set of letters that, when inserted in order, produces a regular and recognisable pattern, often a repeated sequence like ABCPQR.

Given Data / Assumptions:

• Template: _ B C _ Q _ A B _ P _ R.• There are five blanks in total.• Options provide five-letter sequences that must fill the blanks sequentially.• Fixed letters hint at fragments of ABC and PQR.

Concept / Approach:
First, we note that ABC and PQR are common triads used in such patterns. The presence of BC, Q and AB, P, R suggests that the intended full series may be ABCPQRABCPQR or something similar. Therefore, we test each option by inserting it into the blanks, then examine whether the completed pattern is a neat repetition of ABCPQR or another simple block. The option that gives a full, repeated pattern is highly likely to be correct.

Step-by-Step Solution:
Insert option c (APRCQ) into the blanks.Filling the blanks produces the full sequence ABCPQRABCPQR.We can split this as ABCPQR | ABCPQR, which is exactly two repetitions of the same six-letter block.Thus, the completed pattern is a clean repetition of ABCPQR, confirming a very simple and elegant underlying rule.

Verification / Alternative check:
Checking other options yields less regular strings. Option a produces PBCAQRABCPQR, which starts with PBC instead of ABC and breaks the repetition. Option b and option d also introduce irregularities where the first half does not match the second half, and the segment ABCPQR is either incomplete or misordered. In contrast, option c delivers two identical ABCPQR segments in succession, which matches the typical style of well-formed reasoning patterns.

Why Other Options Are Wrong:
Options a, b and d create strings that cannot be viewed as straightforward repetitions of a short block. For example, option a misplaces letters at the start, while others disturb the order of P, Q and R in the middle or at the end of the series. Since we expect a logically simple and symmetric structure, these irregular patterns do not satisfy the requirement of the question.

Common Pitfalls:
A frequent mistake is to focus on making the first few characters look like ABC or PQR without checking the rest of the series. Another pitfall is to ignore the powerful clue of repetition and treat the pattern as random. To solve such questions reliably, candidates should always examine the entire completed string and see whether it can be divided into identical repeating segments.

Final Answer:
APRCQ