Questions: The horses tails were braided with ribbons. A. horse's B. horses

The answer is A. horse's

This option suggests the singular possessive form. If we are referring to the tails of one horse, we would use "horse's" to indicate that the tails belong to that single horse. However, since the sentence refers to multiple tails, it implies that there are multiple horses.

This option is the plural form of "horse" without indicating possession. To correctly show possession for multiple horses, the correct form should be "horses'." The sentence implies that the tails belong to multiple horses, so the correct possessive form should be "horses' tails." However, since the options provided do not include "horses'," the closest correct form based on the options given is "horse's," assuming a singular possessive context.