B is correct.
By looking at the map, we can deduce the answer:
-A is incorrect because the majority of the cities <em>are </em>inside of Asia (India, China, Japan, etc. are all inside of Asia)
-B is correct because most of the cities are inside Asia, most countries with cities are Asian countries.
-C is incorrect because it is only represented by one city, Sao Paulo, Brazil.
-D is incorrect since there are no cities in Africa shown on the map.
Hope this helps! :)
