The correct answer is D.
Both were proxy wars that took place during the Cold War era, characterized by the confrontation between the Eastern bloc of communist countries, leaded by the URSS and the Western group of capitalist countries headed by the US, that took place after WWII, during the second half of the 20th century.
The US and URSS never attacked each other directly because they feared a nuclear war but, instead, they used to participate in proxy wars, by supporting opposite sides.
