Nearly all of the countries that possess a very rapid population growth rate (3.0% and higher) also have populations in which the number of persons under age 15 is

I believe that the answer is Niger.

D.haka is the first answer and a.canberra is the second answer

Sequoia national park  /  inyo national forest, california, u.s. mount whitney is the tallest mountain in california, as well as the highest summit in the contiguous united states and thesierra nevada—with an elevation of 14,505 feet (4,421 m).