The group ___ her to stay.

The correct choice is "advises" because it aligns with the subject-verb agreement required in the sentence. In this context, "the group" is treated as a singular collective noun, and therefore it requires a singular verb form. "Advises" is the third-person singular form of the verb "advise," which is suitable when the subject is a singular entity like "the group."

Using "advise" would imply a plural subject, which does not fit since "the group" acts as one unit. "Advice" is a noun and cannot be used as a verb in this sentence. "Advices" is not grammatically correct as it is not standard to use "advice" in the plural form when referring to advice in general.

Thus, "advises" correctly completes the sentence while adhering to proper grammatical structure.