The Imposition of Standards Is a Way to Establish Nontariff

The imposition of standards is a way to establish nontariff barriers,and the following are examples of the imposition of standards,except for:

A) Japan's refusal to import light mayonnaise containing potassium sorbate.
B) Canada's categorization of orange juice with added calcium as a drug, subject to special requirements.
C) the prohibition of imported drugs at the consumer level in the U.S.
D) tariffs on certain barbiturate imports into the U.S.