Suppose that GARCH $(1,1)$ parameters have been estimated as $=0\mathrm{.}000002,a=0\mathrm{.}04,$ and $=0\mathrm{.}94.$ The current daily volatility is estimated to be $3\mathrm{.}5\%.$ Estimate the volatility per annum that should be used to price a $60-$day option.

a$.50\mathrm{.}8\%$

b$.43\mathrm{.}5\%$

c$.33\mathrm{.}1\%$

d$.18\mathrm{.}9\%$