C is the answer to this question. Nairobi is located at the Southern-Central portion of the country. This is where you can find Nairobi National Park wherein there are different animals that are considered to be endangered. There are also some people who usually go to Nairobi as a jump-off point before they go to another location within the same country.
Some people spend at least a day in Nairobi before exploring other places in Kenya because they believe that a lot of places in the country have a lot of things to offer. There are different itineraries that are available for people who want to explore Kenya in a few days.