The following code has a bug in it$.$ Identify which line has the bug, what the issue is$.$

This code should take in a list of strs$,$ and return a string that is all the words separated by $\text{'}.\text{'}$

so given $[\text{'}$This$\text{'},\text{'}$is$\text{'},\text{'}$an$\text{'},$ 'example'$]$ it should return 'This. is$.$ an$.$ example. $\text{'}$

$1|$ def add$\_$emphasis$($list$\_$of$\_$words$)$:

$2|$ new$\_$sentence $=""$

$3|$ for w in list$\_$of$\_$words:

$4|$ new$\_$sentence $=$ w $+"."$

$5|$ return new$\_$sentence

$6|$ phrase $=[\text{'}$This$\text{'},\text{'}$is$\text{'},\text{'}$an$\text{'},$ 'example'$]$

$7|$ print$($add$\_$emphasis$($phrase$))$

$($If you are tring this in vscode make sure you delete the line numbers I've added$)$

Choice $1$ of $5$: There is no error

Choice $2$ of $5$: Line $3,$ syntax error, the for loops needs to be written differently

Choice $3$ of $5$: Line $4,$ logic error, overwriting value in variable

Choice $4$ of $5$: Line $4,$ runtime error, can't add list of strings to a string

Choice $5$ of $5$: Line $7,$ runtime error, the function isn't being called right