Business groups have told CNBC that the EU must consider retaliatory measures in response to U.S. President Donald Trump's threats to impose tariffs on the bloc.The EU has frozen its EU-US trade deal in response to Trump announcing plans to impose 10% tariffs on six EU nations, alongside the U.K. and Norway from Feb. 1 on Saturday. There have been calls for the bloc to consider using its anti-coercion instrument (ACI), a set of measures that allow it to impose sweeping trade sanctions. "All EU trade defense ...