This is the graph of a sine function, and it has the correct amplitude and period. However, it has been reflected over the x-axis, which would mean it has a negative coefficient. The function $\displaystyle{y}=\frac{{3}}{{2}}{\sin{{\left(\frac{{1}}{{2}}{x}\right)}}}\usepackage{cmbright}\Huge\$ has a positive coefficient, so its graph would have a hill just to the right of the y-axis. The correct answer is the graph with one hill over the interval $\displaystyle{\left[{0},{2}\pi\right]}\usepackage{cmbright}\Huge\$ .