How did each nation recover their wartime losses?

The Aftermath of World War II was the beginning of a new era, defined by the decline of all European colonial empires and simultaneous rise of two superpowers:

Explanation:

Civilian deaths totaled 50-55 million. Military deaths from all causes totaled 21–25 million, including deaths in captivity of about 5 million prisoners of war. Statistics on the number of military wounded are included whenever available. More than half of the total number of casualties are accounted for by the dead of the Republic of China and of the Soviet Union. The government of the Russian Federation in the 1990s published an estimate of USSR losses at 26.6 million, including 8 to 9 million due to famine and disease. These losses are for the territory of the USSR in the borders of 1946–1991, including territories annexed in 1939–40. The People's Republic of China as of 2005 estimated the number of Chinese casualties in the Second Sino-Japanese War from 1937 to 1945 are 20 million dead and 15 million wounded.

i believe the answer is a

the enslaved people onboard suffered from illness with some frequency