Select the option that represents the letters that, when placed from left to right in the blanks below, will complete the letter-series.N_M_N_ MANNA_A

Let's test the given options to find a repeating or logical pattern.The given series is:N _ M _ N _ _ M A N N A _ A _There are $16$ positions in total. Let's break it down into groups of $4$ letters:N_M_ | N__M | ANNA | _A_Let's test option C (ANAMAA):1st blank: A2nd blank: N3rd blank: A4th blank: M5th blank: A6th blank: ASubstituting these into the blanks:N A M N | N A M M — This doesn't form a perfectly regular symmetric pattern.Let's look at the pattern by dividing into groups of $4$ based on a repeating sequence:Let's see if the pattern is N A M N / N A M N / A N N A / M A N A? No.Let's try Option C directly:Placing A, N, A, M, A, A into the blanks:N A M N | N A M M | A N N A | A A A — Incorrect.Let's analyze the letters available. The sequence ends with M A N N A _ A _.Notice the word NAMAN or MANNA.Let's divide into groups of $5$:N _ M _ N | _ _ M A N | N A _ A _Let's test option C again:N A M N N | A M M A N | N A A A A — No.Let's test Option D (ANNANM):N A M N N | A N M A N | N A N A M — No.Let's carefully check the pattern of Option C:If we place the letters of Option C: A, N, A, M, A, AN A M N N A M M A N N A A A A — No clear pattern.Let's try Option A (AANAMN):N A M A N A M M A N N A N A N — No.Let's look at the structure N _ M _ N _ _ M A N N A _ A _.Let's divide into blocks of $4$:If we use Option C (ANAMAA):N A M NN A M MA N N AA A A - Doesn't work.Wait, let's look at Option C again. Let's place it carefully:Blanks are at positions: 2, 4, 6, 7, 13, 15.Let's count positions:1: N2: _3: M4: _5: N6: _7: _8: M9: A10: N11: N12: A13: _14: A15: _Total positions = $15$.Let's check the letters provided in the question:N _ M _ N _ _ M A N N A _ A _1: N2: _3: M4: _5: N6: _7: _8: M9: A10: N11: N12: A13: _14: A15: _Yes, $15$ characters, so $6$ blanks.Let's test Option C: A N AM A A1: N2: A3: M4: N5: N6: A7: M8: M9: A10: N11: N12: A13: A14: A15: ALet's write down the completed string:N A M N N A M M A N N A A A ALet's re-verify Option C as A N A M A A:If the pattern consists of repeating groups or alternating groups:Let's look at blocks of $5$:Block 1: N A M N NBlock 2: A M M A NBlock 3: N A A A ALet's check Option B (ANNMMA):N A M N N N M M A N N A M A ALet's check Option A (AANAMN):N A M A N N A M A N N A M A NLet's look at Option A:N A M A NN A M A NN A M A NWow! Let's check Option A with the original string:Original string: N _ M _ N _ _ M A N N A _ A _If we substitute Option A (A A N A M N):1: N2: A (1st letter)3: M4: A (2nd letter)5: N6: N (3rd letter)7: A (4th letter)8: M9: A10: N11: N12: A13: M (5th letter)14: A15: N (6th letter)Let's read the full string now:N A M A N | N A M A N | N A M A NThis forms a perfect repeating pattern of the word NAMAN three times!