C-11-Q019mediumsingle_mcqThe distance between P(x1,y1)P(x_1, y_1)P(x1,y1) and Q(x2,y2)Q(x_2, y_2)Q(x2,y2) is —a(x2+x1)2+(y2+y1)2\sqrt{(x_2+x_1)^2+(y_2+y_1)^2}(x2+x1)2+(y2+y1)2b(x2−x1)2+(y2−y1)2\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}(x2−x1)2+(y2−y1)2c(x2−x1)2+(y2−y1)2(x_2-x_1)^2+(y_2-y_1)^2(x2−x1)2+(y2−y1)2d∣x2−x1∣+∣y2−y1∣|x_2-x_1|+|y_2-y_1|∣x2−x1∣+∣y2−y1∣