What comprises two-thirds of botswana's land?
a. the mitumba mountains
b. the okavango delta
c. the kalahari desert
d. victoria falls

C. The Kalahari Desert

Explanation:

Botswana is a country located in the southern parts of Africa . The country is a landlocked region as they lack access to the oceans. Botswana shares boundaries with Namibia, South Africa , Zambia and Zimbabwe.  

The Kalahari desert is a desert located in the southern part of Africa and the landscape covers three countries namely Namibia,Botswana and south Africa.

The Kalahari desert  occupies roughly 70 percents of Botswana's land mass . In other words it occupies two-third of  the Botswana's land . The Kalahari desert is a semi arid desert with limited amount of rainfall.

The picture above shows you how Kalahari deserts looks like.  

answer; is roughly two weeks;