In the question given below, the sentence is divided into three parts I, II and III. For each part an alternate statement is also given. You have to determine if a part requires correction, and then mark that as your answer.

Trade quotas are “non-tarif” trade barriers / that limit the number of specific products that / can imported over a set period of time. 

I. Trade quotas are “non-tariff” trade barriers

II. those limit the number of specific products that

III. can imported over a set period of time