5. (10 points) In the sequence $20170 \cdots$, starting from the 5th digit, each digit is the unit digit of the sum of the previous 4 digits, and this sequence can continue indefinitely. From the 5th digit onwards, the array that will definitely not appear in this sequence is ( )
A. 8615
B. 2016
C. 4023
D. 2017
【Analysis】Analyze the properties of odd and even numbers in the result. If one odd number appears among four digits, the next number must be odd. Therefore, the result of two odd numbers plus two even numbers is even. The pattern can be found by enumeration.

【Solution】Solution: Enumeration method
The sum of the digits in 0170 is 8, so the next number is 8.
The sum of the digits in 1708 is 16, so the next number is 6.
The sum of the digits in 7086 is 21, so the next number is 1.
The sum of the digits in 0861 is 15, so the next number is 5.
The sum of the digits in 8615 is 20, so the next number is 0.
The sum of the digits in 6150 is 12, so the next number is 2.
$20170861502 \cdots$
Pattern summary: Check the number of odd numbers in the digits; odd numbers always appear in pairs.
Therefore, the answer is: $B$.