Answer:
A, online
Step-by-step explanation:
Online focus groups give rooms for a wide range of data collection as the internet has made the whole world a (global) village. This means that the whole world is connected without having to be physically present in every part of the world.
For Tara Potter to be able to gather enough data to help with her research, the online focus groups are the best places to gather such data as she has access to a lot of people from diverse geographical locations, thereby saving her the stress of going around various geographical area.
Cheers.