Answer:
A. C. and D.
Step-by-step explanation:
Based on the information provided within the question it can be said that the best ways to discover trends in big cities would be to ask people who have been there, watch TV, or even read newspapers from those cities online. All of these are great options due to the fact that they provide an up-to-date insight on the various different trends and lifestyle choices of individuals in different big cities around the Country.