At the end of the 20th century, relations between japan and russia remained cool because of
a. russian troops stationed on japan s kuril islands.
b. disputed ownership of the kuril islands.
c. failure of arms talks.
d. russia s charges of japanese war crimes.

At the end of the 20th century, relations between Japan and Russia remained cool because of disputed ownership of the Kuril islands. The correct option among all the options that are given in the question is the second option or option "b". This relationship continued between the two countries because of a common interest.