In the given network of AND and OR gates, output Q can be written as (assuming n even)

• A

  $X_0 X_1+X_2 X_3+\ldots X_{n-1} X_n$
• B

  $X_0 X_1 \ldots X_n+X_1 X_2 \ldots X_n+X_2 X_3 \ldots X_n+X_n$
• C

  $X_0 X_1 \ldots X_{n-1}+X_{n-2}+X_{n-2} X_{n-1}+X_n$
• Correct answer
  D

  $X_0 X_1 \ldots X_{n-1}+X_2 X_3 X_5 \ldots X_{n-1}+X_{n-2} X_{n-1}+X_n$

Hence, the correct answer is option: 'D'.