Although High Gain could be a viable answer, given the information D would be the logical answer. Please let me know if I am incorrect.

In order to answer this question correctly, ideally a survey of the campus needs to be analysed before an appropriate action can be implemented (ie the most cost-effective and efficient method to provide wireless coverage). Answer A can be the correct answer, but High Gain (HGA - High Gain Antenna) ma not be the ideal answer as this technology has specific requirements such as the need of open spaces so that there are no hindrances for the directional radio waves. The link below provides more information: What does High-Gain Antenna (HGA) mean? https://www.techopedia.com/definition/26056/high-gain-antenna-hga If the cafe is located within a building or surrounded by other buildings (ie 'obstacles') then maybe an alternative answer may be deemed more suitable (Answer 'D' > Omni-directional). But the underlying gist of thyye matter is that the question made here does not warrant a concrete answer due to its vagueness and places the student taking the exam in an unfair position. In a real-life scenario and network engineer would b far have more relevant data at his or her disposal before making an appropriate decision. Basically this question has been poorly throughout.