What is displayed when the following code is executed?

$0$

day $=23$

if day $\%10==1$:

ending $="$st$"$

elif day $\%10==2$:

ending $="$nd$"$

elif day $\%10==3$:

ending $="$rd$"$

else:

ending $="$th$"$

print$($str$($day$)+$ ending$)$

$23$st

$23$nd

$23$th

$23$rd