There are exactly ten stores and no other buildings on Oak Street. On the north side of the street, from
west to east, are stores 1, 3, 5, 7, and 9; on the south side of the street, also from west to east, are stores
2, 4, 6, 8, and 10. The stores on the north side are located directly across the street from those on the
south side, facing each other in pairs, as follows: 1 and 2; 3 and 4; 5 and 6; 7 and 8; 9 and 10. Each store
is decorated with lights in exactly one of the following colors:
green, red, and yellow. The stores have been decorated with lights according to the following conditions:
No store is decorated with lights of the same color as those of any store adjacent to it.
No store is decorated with lights of the same color as those of the store directly across the street from it.
Yellow lights decorate exactly one store on each side of the street.
Red lights decorate store 4.
Yellow lights decorate store 5.
Suppose that yellow lights decorate exactly two stores, not just one, on the south side of the street and decorate exactly one store on the north side.
If all of the other conditions remain the same, then which one of the following statements must be true?