Which is the best function stub for a function that calculates an item's tax?

Group of answer choices

double ComputeTax$($double itemPrice$)\{$ double TAXRATE $=0\mathrm{.}0675$; return itemPrice $*$ TAXRATE; $\}$

double ComputeTax$($double itemPrice$)\{$ double tax; return tax; $\}$

double ComputeTax$($double itemPrice$)\{$ printf$("$FIXME: Calculate tax

$")$; return $0\mathrm{.}0$; $\}$

double ComputeTax$($double itemPrice$)\{$ double tax $=0\mathrm{.}0$; $\}$