In a particular state, a family of three with total before tax income $($AGI$)$ of $$100,000$ pays an income tax of $$7000,$ with total before tax income$($AGI$)$ of $$50,000$ pays $$3000,$ and with total before tax income$($AGI$)$ of $$20,000$ pays $$1000.$ If typical $($assuming no shifting$),$ these results suggest that the system is:

$$ a$.$ proportional

$$ b$.$ regressive

$$ c$.$ progressive

$$ d$.$ not relied on much as a revenue source compared to user charges

$$ e$.$ b and d$.$