Consider the functions power $($base$,$ exp$)$ and betterPower $($base$,$ exp$)$ that recursively calculate the value of base raised to exp.

def power $(b,x)$ :

if $)=(0$ :

return $1$

return $b^{**}$ power $(b,x-1)$

def betterPower$1(b,x$ : if $)==(0$ :

return $1$

if $x\%2==0$ :

return betterPower $1(b,\frac{x}{\frac{?}{?}}2)*$ betterPower $1(b,\frac{x}{\frac{?}{?}}2)$

else:

return $b**$ betterPower $1(b,\frac{x}{\frac{?}{?}}2)**$ betterPower$1($b$,\frac{x}{\frac{?}{?}}2)$

Suppose a call trace is used to evaluate betterPower $1(3,9)$ as shown below.

line $0$: betterPower $1(3,9)$

line $1$:$=$dots

$...$

line $x$:$=19683$

what is $x?$

$9$

$10$

$5$

$4$