Hua was recently recruited as a customs officer at one of China's major sea ports. He had gone through the training and was now familiar with the duties of customs officers and their role in inspecting imported products coming into the country. On his first day on the job Hua was taken aback when his supervisor instructed him to go slowly in processing the paperwork for a number of containers coming from the United States. As far as Hua could determine these were routine shipments and did not warrant any special caution. The instruction from Hua's supervisor is an example of: Question 22 options: A tariff barrier Corruption A voluntary export restraint A blocked transaction A non-tariff barrier