Calculate the effective rate of interest for the first year, if the rate of interest is $31\mathrm{.}1\%$ p$.$a$.$ compounded semiannually? $($rounding the answer to $6$ significant decimal figures$)$

a$.$

$0\mathrm{.}357282$

b$.$

$0\mathrm{.}358631$

c$.$

$0\mathrm{.}335180$

d$.$

$0\mathrm{.}349187$

e$.$

$0\mathrm{.}359393$