consumer research: green marketing

the Research question I had planned is:
To what extent does green marketing drive customers to buy a sustainable product.

within the research proposal there have to be different questions to answer  the research question, the ones I had planned are:
–
– is green marketing effective in all countries?
– how does the targeted country’s culture influence customers’ purchasing decisions?
– does the price of green marketing affect customer behavior?
– are green products always higher in price?