A. False. The slope is actually -1/2. Each time y goes down by 1, x increases by 2.
B. True. We can use the slope formula to further confirm the slope is -1/2
C. False. The slope is the same throughout the line. So slope of OA = slope of AB. The slope throughout the line is -1/2.
D. False. Same reason as choice C
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Final Answer: Choice B