The term 'splendid isolation' was used to refer the policy of Britain during the 19th century.
During the 19th century, Britain had its empire expanded all over the world. Amost 1/4th of the world population was a part of British empire. Therefore, Britain had no interest in forming allies with other European countries.
The term, therefore, referred to staying out of any territorial disputes between other European nations. Thus option D is correct.
<span>The Italian peninsula is in the center, and generally smaller than the Scandinavian peninsula. A similarity would be that they are both in the northeastern region of Europe.