Benefits of tariffs and trade barriers

A) What are the benefits of tariffs and trade barriers? What purposes do they serve? B) What are the drawbacks of tariffs and trade barriers? Minimum 200 words   What is a specific tariff? What is an ad valorem tariff?   What are the five modes of transportation? What are the pros and cons of each? what you found most interesting on the article https://www.freightwaves.com/news/rail-intermodal-to-struggle-in-2023-consulting-firm-says?utm_source=sfmc&utm_medium=email&utm_campaign=as_week_in_review_1_21_23&utm_term=Rail+intermodal+to+%e2%80%98struggle%e2%80%99+in+2023%2c+consulting+firm+says&utm_id=311615&sfmc_id=305454