D. Why exactly did Russia and Great Britain engage in the Great Game during the 19th century
(1800's)?

Distrust

Explanation:

"The Great Game" was a political and diplomatic confrontation that existed for most of the 19th century between the British Empire and the Russian Empire over Afghanistan and neighbouring territories in Central and South Asia. Russia was fearful of British commercial and military inroads into Central Asia, and Britain was fearful of Russia adding "the jewel in the crown", India, to the vast empire that Russia was building in Asia. This resulted in an atmosphere of distrust and the constant threat of war between the two empires.