If Treasury notes are currently paying $5\mathrm{.}15\%$ and the inflation rate is $2\mathrm{.}20\%,$ what is the approximate real rate of interest? The exact real rate?

a$.2\mathrm{.}95\%$;$2\mathrm{.}89\%$

b$.2\mathrm{.}95\%$;$2\mathrm{.}97\%$

c$.2\mathrm{.}88\%$;$2\mathrm{.}95\%$

d$.2\mathrm{.}89\%$;$2\mathrm{.}95\%$