These look like the graphs of decreasing exponential functions. Therefore, both of these could have the form $\displaystyle{y}={{b}}^{{x}}\usepackage{cmbright}\Huge\$ , with $\displaystyle{0}<{b}<{1}\usepackage{cmbright}\Huge\$ . When $\displaystyle{x}>{0}\usepackage{cmbright}\Huge\$ , Graph B falls below Graph A. This means that the values of the function are smaller. Therefore, the value of the base b should be smaller for Graph B.