score:13
Asia is a lot bigger than the two countries you mention, running from the Mediterranean Sea to Japan and from the Arctic to the south of Indonesia.
If you only visit two countries and can select just those countries it might be best to select the countries you actually plan to visit.
But if you plan to visit South Korea mention it as such, North Korea is a really different country.
In the insurance I usually buy I have three options, within my own country, the continent or the whole world, which makes the choice easy.
Do read if they have a description of 'Asia' so you can see whether that covers what you need and is cheaper than a series of countries you enter yourself.