问题详情

According the interviewee, which is an obstacle of the research？

A．People with different backgrounds have different understanding of healthy food.

B．Supermarkets are afraid that healthy food may bring them less profit.

C．It is hard to trace people"s food choice in small community stores.

D．People find it harder to preserve the healthier food at home.

请帮忙给出正确答案和分析，谢谢！