Which one set of letters when sequentially placed at the gap in the given letter series shall complete it.
d _ c b b _ b d b _ d b d b c _ b d b d _ c d b
Answer & explanation
Correct answer: option 1
d [b] c / b b [d] /b d b / [c] d b / d b c / [b] b d / b d [b] / c d b