Which square (A, B, C, or D) represents the repeating subunit of the polymer shown?
I-0-0
I-0-0
I-U-I
I-O-0
I-O-I
I-O-
I-O-I
I 0
-C-
CH, À CH, ACH,
CH, À
3
CH, H
A
B
С
D
