A body is at rest x = 0. At t = 0, it starts moving in the positive x direction with a constant acceleration. At the same instant, another body passes through x = 0 moving in the positive x-direction with a constant speed. The position of the first body is given by ${\mathrm{x}}_1\left(\mathrm{t}\right)$ after time t and that of the second body by ${\mathrm{x}}_2\left(\mathrm{t}\right)$ after the same time interval. Which of the following graphs correctly describes $({\mathrm{x}}_1 – {\mathrm{x}}_2)$ as a function of time t ?