How do the public services provided in each country compare with each other?

They have different characteristics according to how developed they are.

Explanation:

It is a bit difficult to compare public services in each country because they are really different in each country. For example, you have developed countries like Japan, China, Korea, Germany, Spain, etc. All these countries I have mentioned provide very good public transport like modern trains, subway, bus. Most of them have great public bathrooms in the streets. On the other hand, countries like Argentina, Perú, Bolivia, etc. All these countries are less developed countries and most of them have poor public services.

b.

explanation:

just because.

well, the b sentence is the only one that has sense.