Which one of the following, if substituted for the condition that Hibiscus must be hung somewhere before Katydid but ...

Hello, I’m having trouble understanding why answer B is not correct. If in answer B Gardenias have to be after hibiscus and fence or magnolias is first, would that not be the same that hibiscus has to be before K and can’t be first since GK are next to each other in that order?