Which of the following letter-clusters will replace the question mark (?) in the given series?IBDA, MFHE, QJLI, ?, YRTQ

Let's look at the pattern for each corresponding letter in the clusters:First letter: I $\to$ M $\to$ Q $\to$ ? $\to$ YI(9) $+4=$ M(13)M(13) $+4=$ Q(17)Q(17) $+4=$ U(21)U(21) $+4=$ Y(25)Second letter: B $\to$ F $\to$ J $\to$ ? $\to$ RB(2) $+4=$ F(6)F(6) $+4=$ J(10)J(10) $+4=$ N(14)N(14) $+4=$ R(18)Third letter: D $\to$ H $\to$ L $\to$ ? $\to$ TD(4) $+4=$ H(8)H(8) $+4=$ L(12)L(12) $+4=$ P(16)P(16) $+4=$ T(20)Fourth letter: A $\to$ E $\to$ I $\to$ ? $\to$ QA(1) $+4=$ E(5)E(5) $+4=$ I(9)I(9) $+4=$ M(13)M(13) $+4=$ Q(17)Combining all the letters gives the cluster UNPM.