A researcher wants to estimate the difference in population proportions for two populations using a 95% confidence interval. She samples 875 from the first population and 350 possess the characteristic of interest. She samples 925 from the second population and 416 possess the characteristic of interest. The confidence interval is:

a -.088 to -.012

b -.051 to -.049

c -.096 to -.004

d -.110 to .010