OG详解-OG10 数学1 Q4

Choice A is correct. When a graph is translated up 4 units, each point on the resulting graph is 4 units above the point on the original graph. In other words, the y-value of each point on the graph increases by 4. The graph shown passes through the points(1,-1) ,(2,-2) and (3,-1). It follows that when the graph shown is translated up 4 units, the resulting graph will pass through the points（1,-1+4), (2,-2+4)  and (3,-1+4). These points are (1,3), (2,2)  and (3,3), respectively. Of the given choices, only the graph in choice A passes through the points (1,3),(2,2) and (3,3).
Choice B is incorrect. This is the result of translating the graph down, rather than up, 4 units. Choice C is incorrect. This is the result of translating the graph left,  rather than up, 4 units. Choice D is incorrect. This is the result of translating the graph right, rather than up, 4 units.