What is the annuity factor for an annuity with $12$ periods and periodic discount rate of $2\mathrm{.}56\%?$ a$\mathrm{.}10\mathrm{.}2005$ b$.10\mathrm{.}2206$ c$.10\mathrm{.}2407$ d$.10\mathrm{.}2608$ e$.$ None of the above