Select the option that represents the letters that, when placed from left to right in the same sequence in the blanks below, will complete the letter series.
B _ A_ B _ _ B _ _B A _ B _ M B _

Logic: In this type of series we have to put each option in the blank space when any option give us proper logical series that will be correct option.

From option (A) : AMBBMBAMM

B A AM B B B B M BB A A B MM B M (Not follow logical pattern)

From option (B) : BMABAMBAA

B BA M B A/ B B A M B A/ BB A M BA  (Follows logical pattern)

From option (C) : MABBABAAB

B MAA B B B B ABB A A B A M B B (Not follow logical pattern)

From option (D) : ABAMAABBM

B A AB B A M B A AB A B B B M B M (Not follow logical pattern)

Thus option (B) is correct.