I think that the best answer from the options is the following one:
B. lightly regulated markets depressing wages for unskilled workers
The thing is, unskilled workers cannot really pose many demands for their pay, because they can be replaced by other workers. This is what has led to low wages of the unskilled workers, while increasing the wealth of the richest, who own the production means.
The answer is B. Lake Victoria. If you look at a physical map of Africa, you will get this answer. The Great Rift Valley is through the center of Djibouti. The Indian Ocean is east of INDIA, not even close to Africa. I hope this helps!
Political geography studies all the following except Economies ( answer A). Political geography is concern with study of both spatially uneven outcome of political processes and the ways in which political processes are themselves affected by spatial structure. It also involve study of boundaries and their associated region.
Set this up as
10 = 40 (1/2)t/28
and solve for t in years.
10/40 = (1/2)t/28
log(0.25) = (t/28) log(0.5)
t = 28 log(0.25) / log(0.5) years = 56 years
Test the answer:
56 years = 2(28 years) = 2 half-lives, so the remaining amount should be 1/2 of 1/2 of the initial amount, i.e. 1/4 of the initial amount, and 10 mg = 1/4 of 40 mg.