The following excerpt from the court opinion State vs. Frank was given to you. Can you extract the law from the case and draft the rule from Frank.
"Marilyn fell while walking outside of her doctor's office. She fell because the sidewalk was uneven. Marilyn sustained substantial injures from the fall. To recover her fees, she sued the landlord of the office complex and the Doctor for negligence. The Doctor argued that he was not charged with maintaining the complex and, therefore, not liable. The Court agreed and dismissed the Doctor from the suit early on. Marilyn appealed that decision alleging that the Doctor should be held liable because the Doctor knew of the uneven sidewalk and even told his patients to be cautious. The court held that because the Doctor was making a revenue on patients coming to his office and because the Doctor knew of the uneven sidewalk, the Doctor should be held liable as well for the unsafe sidewalk." State v. Frank.