The impact of the author's choice of words in the line "He reeled, he lurched, he bobbed, he checked;" primarily creates a sense of Brown's uncontrolled motions. The verbs used—"reeled," "lurched," "bobbed," and "checked"—convey a lack of stability and intention in his actions, emphasizing a chaotic or erratic movement. Therefore, the correct answer is:
A. It creates a sense of Brown's uncontrolled motions.