When asked to name a country starting with 'D', my first thought is generally 'Dominican Republic'. When asked for another, I think 'Deutschland', then 'Denmark', and then 'Djibouti'. None of these require much thought for me.
It seems, though, that you can safely assume that Americans will think Denmark first. At any rate, there's a fairly wide-spread game thingy that makes that assumption:
'Write down a country starting with "d", then write down an animal that starts with the second letter of that country, and then write down the colour of that animal. [pause] You have a grey elephant from Denmark.'
I first saw this on Zoom season 2 (1990s version), and my first thought was something along the lines of 'Good thing they had Claudio being the GM rather than a player'.
'Cause Claudio is from the Dominican Republic.
Strange none of his friends were influenced by that fact.
(I never think of 'Dominica'. Had I asked for a fifth, I'd have been stuck for a while. 'Democratic Republic of the Congo' probably would have been my next one.)