"The necessities of our altered relationship to the Pacific Ocean [after the late 1840s] 67 found expression in a comprehensive treaty of friendship commerce, and navigation with the sovereign kingdom of Hawaii. __ The line) from San Francisco to Honolulu lin Hawaiil marks the natural limit of the ocean belt within which our trade with leastern Asia] must flow. __ When we survey the stupendous progress made by the western coast during the thirty years of its national life as a part of our dominion, __ it is not easy to set a limit to its commercial activity or foresee a check to its maritime supremacy in the waters of [eastern Asia], so long as those waters afford as now, a free and neutral scope for our peaceful trade __ The United States) firmly believes that the position of the Hawaiian Islands as the key to the dominion of the American Pacific demands their neutrality, to which end it will earnestly cooperate with the native government. And if, through any cause the maintenance of such a position of neutrality should be found by Hawaii to be impracticable, this government would then unhesitatingly meet the altered situation by seeking an avowedly American solution for the grave issues presented." Secretary of State James G Blaine, letter to James M. Comly, United States ambassador to Hawaii, 1881 The foreign policy ideas in the excerpt are best explained by which of the following nineteenth-century developments? A A response to changing immigration patterns B An attempt to end Reconstruction policies C A reaction to expanding United States economic activity D An effort to enact political reforms in urban areas