Which asian country defeated russia in war and gained control of manchuria and korea?
a. thailand
b. japan
c. indochina
d. taiwan

Iwon't go into too much details but the asian country that defeated russia in war, namely the russo-japanese war(1904-05) was japan. 
it was a conflict based on good military strategy. it all started because japan wanted korea as a province but russia did not allow that to happen so japan tried to negotiate to get korea in exchange that russia could keep manchuria but russia refused and negotiations broke down so japan thought of an . 
japan knew that russia had a massive army but japan had a very mobile and well trained army so  they used that to their advantage. so the japanese fleet open fired on the russia eastern fleet in port arthur which eventually got destroyed. as russia suffered humiliating defeats, the country thought it could beat japan but japans strategy proved superior so they defeated russia in many battles. so in order to prevent a total "defeat", russia asked for peace (u.s as the middleman)which gave japan some of what it wanted but not all. this caused both countries to be