Based upon samples drawn from corresponding populations, in which of the following scenarios will conducting a two-proportion z-test be the most appropriate?
A. To compare the proportions of low-income families between British Columbia and Ontario.
B. To compare the proportion of low-income families in British Columbia with a known national proportion.
C. To compare the mean annual income of British Columbians with a known national mean.
D. To compare the mean annual income of male British Columbians with that of female British Columbians.
E. To compare the proportion of low-income families with that of high-income families in British Columbia.