The terms in the given alpha-numeric series follow a certain pattern. However, some terms are missing. Choose the correct sequence of the missing terms from the options given below:

Z_25YB23XC_W_19_E17

Looking at the series: Z_25YB23XC_W_19_E17

Let me identify the pattern by grouping the terms into triplets (Letter, Letter, Number):

Given series with blanks numbered:

• Z [1] 25
• Y B 23
• X C [2]
• W [3] 19
• [4] E 17

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Examining the numbers in each triplet:

25, 23, [2], 19, 17

The numbers decrease by 2 each time:

$25 - 2 = 23$

$23 - 2 = 21$

$21 - 2 = 19$

$19 - 2 = 17$

Therefore, blank [2] = 21

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Examining the first letters of each triplet:

Z, Y, X, W, [4]

These are consecutive letters going backwards in the alphabet.

Therefore, blank [4] = V

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Examining the second letters of each triplet:

[1], B, C, [3], E

These are consecutive letters going forwards in the alphabet: A, B, C, D, E

Therefore, blank [1] = A and blank [3] = D

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The complete series is:

(Z, A, 25), (Y, B, 23), (X, C, 21), (W, D, 19), (V, E, 17)

The missing terms in order are: A, 21, D, V

This matches Option 4.