Answer: B. Remove the principle of "mutual recognition" as it pertains to product standards
Explanation:The Single European Act was an act with the purpose of having one single market. This market refers to the European Union as one body without any internal borders, regulatory obstacles etc. to the free movement of goods and services thereby stimulating competition, trade, improved efficiency, quality, and price cuts and to add new momentum to European integration and to complete the internal market.
One of the purpose of the act was to apply (not remove) the principle of "mutual recognition" to product standards which should be accepted across the Union, provided it met basic requirements in such matters as health and safety.
Others include to move all frontier controls among countries; institute open public procurement to nonnational suppliers; lift barriers to competition in the retail banking and insurance businesses; remove all restrictions on foreign exchange transactions between member countries; and to abolish restrictions on cabotage.