Refrez Inc., a U$.$S$.-$based cereal manufacturer, begins selling its products in China. While people in the United States eat cereal with cold milk, the people of China eat cereal with hot milk. Refrez Inc. believed that everyone used cold milk with cereal and did not modify its product according to people's preferences. As a result, it witnessed a decline in sales in China. In this scenario, what was the obstacle to defining the research problem?

Multiple choice question.

The Monroe Doctrine prevented researchers from using research tools in China.

Researchers ensured that the research problem definition covered the whole range of response possibilities.

Researchers focused on the influence of local culture on the research problem.

The research problem was clouded by researchers' self$-$reference criterion.