Complete the code to append the values in my$\_$list to a file named my$\_$data.txt with one value in each line.

$m{y}_l$ist $=[10,20,30,50]$

$xxxxxxx$

a$.$

file $=$ open$(\text{'}$my$\_$data.txt$\text{'},\text{'}$a$+\text{'})$

for i in my$\_$list:

file.write$($i$)$

b$.$ file $=$ open$(\text{'}$my$\_$data.txt$\text{'},\text{'}$w$\text{'})$

for i in my$\_$list:

file.write$($str$($i$)+\text{'}\frac{?}{?}$

${?}^{\text{'}}$

c$.$

file $=$ open$(\text{'}$my$\_$data.txt$\text{'},\text{'}$a$+\text{'})$

for i in my list:

file.write$($str$($i$)+\text{'}\}$

${(}^{\text{'}}$

d$.)$

for i in my$\_$list:

file.write$($i$)$