A letter series is given below in which some letters are missing. Select the option that gives the letters that can fill these blanks in that order.

q_qa_dq_qd_aqdq_qdq_qd_c

dqcqcaq

The given series is q_qa_dq_ / qd_abdq_ / qdq_qd_c

On observing it closely, we can complete the series as: qdqaqdqc / qdqaqdqc / qdqaqdqc

So, dqcqcaq