I instinctively want to believe the kimchi hypothesis, only because I eat a lot of it myself.

Good point about a).

c) 'Respectable' here is a purely comparative term. I'm taking my figures from Worldometers, according to which the UK rate of tests per million of population (if we exclude very small countries with populations of less than a million in total) is fourth, after Bahrain, Denmark and Singapore. Of course that raw figure hides a lot of information about access, distribution, how many actual people are getting tested as opposed to repeat tests on the same people, etc.