Which of the following observations is not made by Swati Dhingra and Nikhil Datta with regard to post-Brexit trade deals? a. UK trade with China would have to increase tenfold to reach the level of UK trade with the EU. b. Low MFN tariffs mean that a UK-US trade deal would have to address non-tariff barriers. c. The UK could unilaterally liberalize by cutting tariffs on services, which constitute 80 percent of the UK economy. d. Non-tariff barriers in services between the US and EU are estimated to be equivalent to trade costs of 8 to 47 percent