Based on historical records, all of the following contributed to the Massacre at Wounded Knee EXCEPT "<u>a sneak attack of the US army against the Sioux in the dead of night."</u>
This is because the Wounded Knee Massacre occurred in the morning on December 29th, 1890.
The fight and massacred started after an accidental firing from a Native Indian named Black Coyote during a standoff between the U.S. Army and the Native Americans.
Before the massacre, the Sitting Bull (a Lakota Chief) was killed on December 15th, 1890, when Lt. Bullhead and officer Red Tomahawk shot him during his arrest.
Also, the white settlers' feared the Ghost Dance, thinking the Native Americans (Lakota) were using Ghost Dance to plan and prepare for war.
In the end, about 300 Lakota people were massacred, with more than half of them women and children.
Hence, in this case, it is concluded that the correct answer is option B. "<u>a sneak attack of the US army against the Sioux in the dead of night."</u>
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