in kazakhstan,________led to radiation pollution.

d.weapons transport systems
this is my answer

I don't know. What are your other choices?

a. nuclear weapons testing

b. biological weapons
c. uraniun mines

I disagree.

http://www.nationsencyclopedia.com/Asia-and-Oceania/Kazakhstan-ENVIRONMENT.html#b

but all they talk about is weapons they don't say what kind.

unless its c. but they don't say nothing about that either.

nevermind its a. i read the info you gave me and it says nuclear weapons.

Right.

Radiation pollution in Kazakhstan (so called Semipolatinsk Test site). The primary testing venue for the Soviet Union's nuclear weapons. The Soviet Union conducted 456 nuclear tests at Semipalatinsk from 1949 until 1989 with little regard for their effect on the local people or environment. The full impact of radiation exposure was hidden for many years by Soviet authorities and has only come to light since the test site closed in 1991.