Which one most appropriate dynamic system?

A)
y(n) = x(n)
B)
y(n) + y(n - 1)
C)
y(n) + y(n - 1) + y(n + 1)
D)
y(n) + y(n - 1) + y(n + 3) = 0

Correct Answer : Option (C) :   y(n) + y(n - 1) + y(n + 1)


Explanation : Because present output of y(n) depend upon past y(n - 1) and future y(n + 1).