C-10-Q032mediumsingle_mcqThe formula for (nr)\binom{n}{r}(rn) is —an!r!\dfrac{n!}{r!}r!n!bn!(n−r)!\dfrac{n!}{(n-r)!}(n−r)!n!cn!r!(n−r)!\dfrac{n!}{r!(n-r)!}r!(n−r)!n!dr!n!(n−r)!\dfrac{r!}{n!(n-r)!}n!(n−r)!r!