Select the letter-cluster from among the given options that can replace the question mark (?) in the following series. NIR, JGN, FEJ, ?
BCF

The logic followed here is:

Hence, 'BCF' is the correct answer.
A series is given with some letters missing. Choose the correct alternative from the given ones that will complete the series:
BR __ __ NB __ O __ NBA series is given with some letters missing. Choose the set of letters which when sequentially placed shall complete it .
a __ __ dba __ __ bcad __ __ da __ __ cdIn the following letter series, some of the letters are missing which are given in that order as one of the alternatives below It. Choose the correct alternative
_ a _ b _ abaa _ bab _ abbSelect the combination of letters that when sequentially placed in the blanks of the given series will complete the series.
Q _ P _ M _ A _ T _ Q A _ T M
In the series _b_a_ba_b_abab_aab;
fill in the six blanks ( _ ) using one of the following given four choices such that the series follows a specific order.